// check for empty field
function empty(field,display)
{ 
 
if(field.value!="")
{}
else
   {
     alert( "Field "+display+" should not be empty");
     field.focus();
     return false;
   }
   
return true;  

}

//check for characters
function characters(field,display)
 {
   var chkStr=field.value;
   var i;
   for(i=0;i<chkStr.length;i++)
    {
      var char=chkStr.substring(i,i+1);
      var FDOT=chkStr.indexOf(".");
      var SDOT=chkStr.indexOf(".",(FDOT+1));
      var Uscore=chkStr.indexOf("_")
     if(((char>="a" || "z"<=char)|| (char>="A" || "Z"<=char)||(char ==".")||(char==" ")) && (SDOT!=(FDOT+1))
	 && (FDOT!=0)&&(Uscore==-1))
       {}
    else
   {
     alert("Field "+display+" should be characters only");
     field.focus();
     return false;
   }
   }
    return true;
}

//e-mail validation
function mailcheck(field,display)
  {  
  var check=field.value;
  var Fdot=check.indexOf(".");
  var Sdot=check.indexOf(".",(Fdot+1));
  var invalid="~!#$%^&*()-+|\=`/?,><;:}{][\'\"";
  var ok = "yes";
  var special;
  var i;
  for(i=0;i<check.length;i++)
  {
  special= "" + check.substring(i, i+1);
  if((invalid.indexOf(special)>=0)) ok = "no";
  } 
  if ((ok=="yes") && (check.indexOf(" ")!=-1
     ||check.indexOf("@")==0
     ||check.indexOf("@")==-1||check.indexOf("@")!=check.lastIndexOf("@")
     ||check.indexOf(".")==0||check.indexOf(".")==-1
     ||check.indexOf("@")==(check.indexOf(".")-1)
     ||check.indexOf(".")==(check.indexOf("@")-1)
     ||check.indexOf(".")<check.indexOf("@")
     ||check.lastIndexOf(".")==(check.length-1)
     ||check.lastIndexOf("_")==(check.length-1)
     ||Sdot==(Fdot+1)))
  {
		ok = "no";
  }
  if(check.substring(0,1) == "_" ) ok="no";
  if(ok=="no")
  {
    alert("Invalid Email ID");
    field.focus();
    return false;
  }
    
    return true;
  } 
 //check for number
 function  number(field,display)
   {
     var chkStrvalue=field.value;
     var i;
     for(i=0;i<chkStrvalue.length;i++)
  {
     var num=chkStrvalue.substring(i,i+1);
     if((num>="0"&& num<="9")||num=="-"||num==" ")
  {}
 else
  {
     alert("Field "+display+" should be of Numbers only");
     field.focus();
     return false;
  }
  }
     return true;
  }
  
// check for selection
function checkselect()
{
  var num = checkselect.arguments.length;
  if (num == 2){

	if(checkselect.arguments[0] == ""){
		alert("Please Select the "+ checkselect.arguments[1] + " Field");
		return false;
        } else return true;

  } else {

	if(checkselect.arguments[0] == "" || checkselect.arguments[1] == "" || checkselect.arguments[2] == ""){
		alert("Please Select the "+ checkselect.arguments[3] + " Field");
		return false;
        } else return true;
}

}
//Validating the Date Selected
	function ChkMonthDays(SelDay,MonIndex,SelYear)
	{
	   var ok="true";
		if(MonIndex==4 || MonIndex==6 || MonIndex==9 || MonIndex==11)
		{
			if(parseInt(SelDay)==31)
			{
				ok="false";			
			}
		} 
		if(MonIndex==2)	//For Feb.
		{
			if((parseInt(SelYear) % 4)!=0)
			{
				if(parseInt(SelDay)>28)
				{
					ok="false";
				}
			}
			else if((parseInt(SelYear) % 400)==0)
			{
				if(parseInt(SelDay)>29)
				{
					ok="false";			
				}
			}
			else if((parseInt(SelYear) % 100)==0)
			{
				if(parseInt(SelDay)>28)
				{
					ok="false";			
				}
			}
			else
			{
				if(parseInt(SelDay)>29)
				{
					ok="false";			
				}
			}
		}
		if(ok=="false")
		{
			alert("Invalid Date");
			return false;
		}
		else return true;	
	}