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;
	}
	var itemobj=this.formobj[itemname];

    if(itemobj.length && isNaN(itemobj.selectedIndex) )
    
	{
		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;
}
 
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;
}
      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(isNaN(objCompare.value)) 
{
        alert(objCompare.name+": Should be a number ");
        return false;
}
}
   var cmpstr="";
   switch(strvalidator)
{
       case "eqelmnt":
			{
			   if(objValue.value !=objCompare.value)
			{
 	 		      cmpstr=" should be equal to ";
			      bRet=false;
			}
			   break;
			}
		case "ltelmnt":
			{
			if(eval(objValue.value)>=eval(objCompare.value)) 
				{
			       cmpstr=" should be less than ";
			       bRet=false;					
				}
			  break;
			}
		case "leelmnt":
			{
				if(eval(objValue.value)>eval(objCompare.value)) 
				{
			       cmpstr=" should be less than or equal to";
			       bRet=false;					
				}
			  break;
			}
		case "gtelmnt":
			{
				if(eval(objValue.value)<=eval(objCompare.value)) 
				{
			       cmpstr=" should be greater than";
			       bRet=false;					
				}
			  break;
			}
		case "geelmnt":
			{
				if(eval(objValue.value)<eval(objCompare.value)) 
				{
			       cmpstr=" should be greater than or equal to";
			       bRet=false;					
				}
			  break;
			}
		case "neelmnt":
			{
			   if(objValue.value.length>0 &&
			     objCompare.value.length>0 &&
			     objValue.value==objCompare.value)
			{
 	 		      cmpstr=" should be different from ";
			      bRet=false;
			}
			   break;			
			}			
}
   if(bRet==false)
{
      if(!strError||strError.length==0)
	{
	    strError=objValue.name+cmpstr+objCompare.value;
	}
	  alert(strError);
}
   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++;
		}
		}
	}
	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;
		}
		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(idxchk>=0)
		{
		  if(objcheck[idxchk].checked=="1")
		{
		    pass=false;
		}
		}
	}
	else
	{
		if(objValue.checked=="1")
		{
			pass=false;
		}
	}
	if(pass==false)
	{
     if(!strError||strError.length==0) 
{
        	strError="Can't Proceed as you selected "+objValue.name;
}
	  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";
}
       alert(strError);
       ret=false;
}
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 ";
}
      alert(strError+"\n[Current length = "+objValue.value.length+" ]");
      ret=false;
}
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  ";
}
      alert(strError+"\n[Current length = "+objValue.value.length+" ]");
      ret=false;
}
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;
}
      alert(strError+"\n [Error character position "+eval(charpos+1)+"]");
      ret=false;
}
 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 ";
}
       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;
	}
	  else
	  if(eval(objValue.value)>=eval(strLessThan)) 
	{
	    if(!strError||strError.length==0) 
	{
	      strError=objValue.name+" : value should be less than "+strLessThan;
	}
	    alert(strError);
	    ret=false;
	}
return ret;
}

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


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 "dontselectchk":
		{
			ret=TestDontSelectChk(objValue,cmdvalue,strError)
			break;
		}
		case "selmin":
		{
			ret=TestSelMin(objValue,cmdvalue,strError);
			break;
		}
		case "selone":
		{
			ret=TestSelectOneRadio(objValue,strError);
		    break;
		}		 
		
		case "eqelmnt":
		case "ltelmnt":
		case "leelmnt":
		case "gtelmnt":
		case "geelmnt":
		case "neelmnt":
		{
		    return TestComparison(objValue,cmdvalue,command,strError);
    		break;
		}
}
    return ret;
}