function Validator(frmname)
{
    this.formobj=document.forms[frmname];
	if(!this.formobj)
	{
	  alert("BUG: couldnot get Form object "+frmname);
		return;
	}
	if(this.formobj.onsubmit)
	{
	 this.formobj.old_onsubmit = this.formobj.onsubmit;
	 this.formobj.onsubmit=null;
	}
	else
	{
	 this.formobj.old_onsubmit = null;
	}
	this.formobj.onsubmit=form_submit_handler;
	this.addValidation = add_validation;
	this.setAddnlValidationFunction=set_addnl_vfunction;
	this.clearAllValidations = clear_all_validations;
}
function set_addnl_vfunction(functionname)
{
  this.formobj.addnlvalidation = functionname;
}
function clear_all_validations()
{
	for(var itr=0;itr < this.formobj.elements.length;itr++)
	{
		this.formobj.elements[itr].validationset = null;
	}
}
function form_submit_handler()
{
	for(var itr=0;itr < this.elements.length;itr++)
	{
		if(this.elements[itr].validationset &&
	   !this.elements[itr].validationset.validate())
		{
		  return false;
		}
	}
	if(this.addnlvalidation)
	{
	  str =" var ret = "+this.addnlvalidation+"()";
	  eval(str);
    if(!ret) return ret;
	}
	return true;
}
function add_validation(itemname,descriptor,errstr)
{
	if(!this.formobj)
	{
		alert("BUG: the form object is not set properly");
		return;
	}//if
	var itemobj = this.formobj[itemname];

    if(itemobj.length && isNaN(itemobj.selectedIndex) )
    //for radio button; don't do for 'select' item
	{
		itemobj = itemobj[0];
	}
	if(!itemobj)
	{
		alert("BUG: Couldnot get the input object named: "+itemname);
		return;
	}

	if(!itemobj.validationset)
	{
		itemobj.validationset = new ValidationSet(itemobj);
	}
	itemobj.validationset.add(descriptor,errstr);
}
function ValidationDesc(inputitem,desc,error)
{
    this.desc=desc;
	this.error=error;
	this.itemobj = inputitem;
	this.validate=vdesc_validate;
}
function vdesc_validate()
{
 if(!validateInput(this.desc,this.itemobj,this.error))
 {
    this.itemobj.focus();
		return false;
 }
 return true;
}
function ValidationSet(inputitem)
{
    this.vSet=new Array();
	this.add= add_validationdesc;
	this.validate= vset_validate;
	this.itemobj = inputitem;
}
function add_validationdesc(desc,error)
{
  this.vSet[this.vSet.length]=
  new ValidationDesc(this.itemobj,desc,error);
}
function vset_validate()
{
   for(var itr=0;itr<this.vSet.length;itr++)
	 {
	   if(!this.vSet[itr].validate())
		 {
		   return false;
		 }
	 }
	 return true;
}
/*  checks the validity of an email address entered
*   returns true or false
*/
function validateEmail(email)
{
    var splitted = email.match("^(.+)@(.+)$");
    if(splitted == null) return false;
    if(splitted[1] != null )
    {
      var regexp_user=/^\"?[\w-_\.]*\"?$/;
      if(splitted[1].match(regexp_user) == null) return false;
    }
    if(splitted[2] != null)
    {
      var regexp_domain=/^[\w-\.]*\.[A-Za-z]{2,4}$/;
      if(splitted[2].match(regexp_domain) == null)
      {
	    var regexp_ip =/^\[\d{1,3}\.\d{1,3}\.\d{1,3}\.\d{1,3}\]$/;
	    if(splitted[2].match(regexp_ip) == null) return false;
      }// if
      return true;
    }
return false;
}

function TestComparison(objValue,strCompareElement,strvalidator,strError)
{
   var bRet=true;
   var objCompare=null;
   if(!objValue.form)
   {
      alert("BUG: No Form object!");
	  return false
   }
   objCompare = objValue.form.elements[strCompareElement];
   if(!objCompare)
   {
     alert("BUG: Element with name"+strCompareElement+" not found !");
     return false;
   }
   if(strvalidator != "eqelmnt" &&
   	  strvalidator != "neelmnt")
   {
      if(isNaN(objValue.value))
      {
        alert(objValue.name+": Should be a number ");
        return false;
      }//if
      if(isNaN(objCompare.value))
      {
        alert(objCompare.name+": Should be a number ");
        return false;
      }//if
   }//if
   var cmpstr="";
   switch(strvalidator)
   {
       case "eqelmnt":
			{
			   if(objValue.value != objCompare.value)
			   {
 	 		      cmpstr = " should be equal to ";
			      bRet = false;
			   }//if
			   break;
			}//case
		case "ltelmnt":
			{
			if(eval(objValue.value) >= eval(objCompare.value))
				{
			       cmpstr =  " should be less than ";
			       bRet = false;
				}
			  break;
			}//case
		case "leelmnt":
			{
				if(eval(objValue.value) >  eval(objCompare.value))
				{
			       cmpstr =  " should be less than or equal to";
			       bRet = false;
				}
			  break;
			}//case
		case "gtelmnt":
			{
				if(eval(objValue.value) <=  eval(objCompare.value))
				{
			       cmpstr =  " should be greater than";
			       bRet = false;
				}
			  break;
			}//case
		case "geelmnt":
			{
				if(eval(objValue.value) < eval(objCompare.value))
				{
			       cmpstr =  " should be greater than or equal to";
			       bRet = false;
				}
			  break;
			}//case
		case "neelmnt":
			{
			   if(objValue.value.length > 0 &&
			     objCompare.value.length > 0 &&
			     objValue.value == objCompare.value)
			   {
 	 		      cmpstr = " should be different from ";
			      bRet = false;
			   }//if
			   break;
			}
   }//switch
   if(bRet==false)
   {
      if(!strError || strError.length==0)
	  {
	    strError = objValue.name + cmpstr + objCompare.value;
	  }//if
	  alert(strError);
   }//if
   return bRet;
}
function TestSelMin(objValue,strMinSel,strError)
{
    var bret = true;
	var objcheck = objValue.form.elements[objValue.name];
	var chkcount =0;
	if(objcheck.length)
	{
		for(var c=0;c < objcheck.length;c++)
		{
		   if(objcheck[c].checked == "1")
		   {
		     chkcount++;
		   }//if
		}//for
	}
	else
	{
	  chkcount = (objcheck.checked == "1")?1:0;
	}
	var minsel = eval(strMinSel);
	if(chkcount < minsel)
	{
		if(!strError || strError.length ==0)
		{
			strError = "Please Select atleast"+minsel+" check boxes for"+objValue.name;
		}//if
		alert(strError);
		bret = false;
	}
	return bret;
}

function TestDontSelectChk(objValue,chkValue,strError)
{
    var pass=true;
	var objcheck = objValue.form.elements[objValue.name];
    if(objcheck.length)
	{
		var idxchk=-1;
		for(var c=0;c < objcheck.length;c++)
		{
		   if(objcheck[c].value == chkValue)
		   {
		     idxchk=c;
			 break;
		   }//if
		}//for
		if(idxchk>= 0)
		{
		  if(objcheck[idxchk].checked=="1")
		  {
		    pass=false;
		  }
		}//if
	}
	else
	{
		if(objValue.checked == "1")
		{
			pass=false;
		}//if
	}//else
	if(pass==false)
	{
     if(!strError || strError.length ==0)
        {
        	strError = "Can't Proceed as you selected "+objValue.name;
        }//if
	  alert(strError);

	}
    return pass;
}

function TestRequiredInput(objValue,strError)
{
 var ret = true;
    if(eval(objValue.value.length) == 0)
    {
       if(!strError || strError.length ==0)
       {
         strError = objValue.name + " : Required Field";
       }//if
       alert(strError);
       ret=false;
    }//if
return ret;
}

function TestMaxLen(objValue,strMaxLen,strError)
{
 var ret = true;
    if(eval(objValue.value.length) > eval(strMaxLen))
    {
      if(!strError || strError.length ==0)
      {
        strError = objValue.name + " : "+ strMaxLen +" characters maximum ";
      }//if
      alert(strError + "\n[Current length = " + objValue.value.length + " ]");
      ret = false;
    }//if
return ret;
}

function TestMinLen(objValue,strMinLen,strError)
{
 var ret = true;
    if(eval(objValue.value.length) <  eval(strMinLen))
    {
      if(!strError || strError.length ==0)
      {
        strError = objValue.name + " : " + strMinLen + " characters minimum  ";
      }//if
      alert(strError + "\n[Password should contain 6-12 characters .Current length = " + objValue.value.length + " ]");
      ret = false;
    }//if
return ret;
}

function TestInputType(objValue,strRegExp,strError,strDefaultError)
{
   var ret = true;

    var charpos = objValue.value.search(strRegExp);
    if(objValue.value.length > 0 &&  charpos >= 0)
    {
     if(!strError || strError.length ==0)
      {
        strError = strDefaultError;
      }//if
      alert(strError + "\n [Error character position " + eval(charpos+1)+"]");
      ret = false;
    }//if
 return ret;
}

function TestEmail(objValue,strError)
{
var ret = true;
     if(objValue.value.length > 0 && !validateEmail(objValue.value)	 )
     {
       if(!strError || strError.length ==0)
       {
          strError = objValue.name+": Enter a valid Email address ";
       }//if
       alert(strError);
       ret = false;
     }//if
return ret;
}

function TestTermsandconditions1(objValue,strError)
{
  // alert("itemobj " +objValue.name);
  // return false;
   var ret = true;
   strError = "Please accept the terms and conditions to proceed further";
   if(!objValue.checked)
     {
     	alert(strError);
     	ret = false;
     }
  return ret;   
}
function TestTermsandconditions2(objValue,strError)
{
   //alert("itemobj " +objValue.name);
   //return false;
   var ret = true;
   strError = "Please accept the terms and conditions to proceed further";
   if(!objValue.checked)
     {
     	alert(strError);
     	ret = false;
     }
  return ret;   
}


function TestLessThan(objValue,strLessThan,strError)
{
var ret = true;
	  if(isNaN(objValue.value))
	  {
	    alert(objValue.name+": Should be a number ");
	    ret = false;
	  }//if
	  else
	  if(eval(objValue.value) >=  eval(strLessThan))
	  {
	    if(!strError || strError.length ==0)
	    {
	      strError = objValue.name + " : value should be less than "+ strLessThan;
	    }//if
	    alert(strError);
	    ret = false;
	   }//if
return ret;
}

function TestGreaterThan(objValue,strGreaterThan,strError)
{
var ret = true;
     if(isNaN(objValue.value))
     {
       alert(objValue.name+": Should be a number ");
       ret = false;
     }//if
	 else
     if(eval(objValue.value) <=  eval(strGreaterThan))
      {
        if(!strError || strError.length ==0)
        {
          strError = objValue.name + " : value should be greater than "+ strGreaterThan;
        }//if
        alert(strError);
        ret = false;
      }//if
return ret;
}

function TestRegExp(objValue,strRegExp,strError)
{
var ret = true;
    if( objValue.value.length > 0 &&
        !objValue.value.match(strRegExp) )
    {
      if(!strError || strError.length ==0)
      {
        strError = objValue.name+": Invalid characters found ";
      }//if
      alert(strError);
      ret = false;
    }//if
return ret;
}
function TestDontSelect(objValue,index,strError)
{
var ret = true;
     if(objValue.selectedIndex == null)
     {
       alert("BUG: dontselect command for non-select Item");
       ret = false;
     }
	 else
     if(objValue.selectedIndex == eval(index))
     {
      if(!strError || strError.length ==0)
       {
       strError = objValue.name+": Please Select one option ";
       }//if
       alert(strError);
       ret =  false;
      }
return ret;
}

function TestSelectOneRadio(objValue,strError)
{
	var objradio = objValue.form.elements[objValue.name];
	var one_selected=false;
	for(var r=0;r < objradio.length;r++)
	{
	  if(objradio[r].checked == "1")
	  {
	  	one_selected=true;
		break;
	  }
	}
	if(false == one_selected)
	{
      if(!strError || strError.length ==0)
       {
	    strError = "Please select one option from "+objValue.name;
	   }
	  alert(strError);
	}
return one_selected;
}

//*  Checks each field in a form
function validateInput(strValidateStr,objValue,strError)
{
    var ret = true;
    var epos = strValidateStr.search("=");
    var  command  = "";
    var  cmdvalue = "";
    if(epos >= 0)
    {
     command  = strValidateStr.substring(0,epos);
     cmdvalue = strValidateStr.substr(epos+1);
    }
    else
    {
     command = strValidateStr;
    }

    switch(command)
    {
        case "req":
        case "required":
         {
		   ret = TestRequiredInput(objValue,strError)
           break;
         }
        case "maxlength":
        case "maxlen":
          {
			 ret = TestMaxLen(objValue,cmdvalue,strError)
             break;
          }
        case "minlength":
        case "minlen":
           {
			 ret = TestMinLen(objValue,cmdvalue,strError)
             break;
           }
        case "alnum":
        case "alphanumeric":
           {
				ret = TestInputType(objValue,"[^A-Za-z0-9]",strError,
						objValue.name+": Only alpha-numeric characters allowed ");
				break;
           }
        case "alnum_s":
        case "alphanumeric_space":
           {
				ret = TestInputType(objValue,"[^A-Za-z0-9\\s]",strError,
						objValue.name+": Only alpha-numeric characters and space allowed ");
				break;
           }
        case "num":
        case "numeric":
           {
                ret = TestInputType(objValue,"[^0-9]",strError,
						objValue.name+": Only digits allowed ");
                break;
           }
        case "alphabetic":
        case "alpha":
           {
                ret = TestInputType(objValue,"[^A-Za-z]",strError,
						objValue.name+": Only alphabetic characters allowed ");
                break;
           }
        case "alphabetic_space":
        case "alpha_s":
           {
                ret = TestInputType(objValue,"[^A-Za-z\\s]",strError,
						objValue.name+": Only alphabetic characters and space allowed ");
                break;
           }
        case "email":
          {
			   ret = TestEmail(objValue,strError);
               break;
          }
        case "lt":
        case "lessthan":
         {
    	      ret = TestLessThan(objValue,cmdvalue,strError);
              break;
         }
        case "gt":
        case "greaterthan":
         {
			ret = TestGreaterThan(objValue,cmdvalue,strError);
            break;
         }
        case "regexp":
         {
			ret = TestRegExp(objValue,cmdvalue,strError);
           break;
         }
        case "dontselect":
         {
			 ret = TestDontSelect(objValue,cmdvalue,strError)
             break;
         }
         
         case "Y":
	 {
	 	  	ret = TestTermsandconditions1(objValue,strError)
	     break;   	
         }
         case "N":
	 {
	          	ret = TestTermsandconditions2(objValue,strError)
	     break;	
         }
         
		case "dontselectchk":
		{
			ret = TestDontSelectChk(objValue,cmdvalue,strError)
			break;
		}
		case "selmin":
		{
			ret = TestSelMin(objValue,cmdvalue,strError);
			break;
		}
		case "selone":
		{
			ret = TestSelectOneRadio(objValue,strError);
		    break;
		}
		//Comparisons
		case "eqelmnt":
		case "ltelmnt":
		case "leelmnt":
		case "gtelmnt":
		case "geelmnt":
		case "neelmnt":
		{
		    return TestComparison(objValue,cmdvalue,command,strError);
    		break;
		}
    }//switch
    return ret;
}