var numb = '0123456789';
var lwr = 'abcdefghijklmnopqrstuvwxyz';
var upr = 'ABCDEFGHIJKLMNOPQRSTUVWXYZ';

function isValid(parm,val) {
  if (parm == "") return false;
  for (i=0; i<parm.length; i++) {
    if (val.indexOf(parm.charAt(i),0) == -1) return false;
  }
  return true;
}

function isNum(parm) {return isValid(parm,numb);}
function isLower(parm) {return isValid(parm,lwr);}
function isUpper(parm) {return isValid(parm,upr);}
function isAlpha(parm) {return isValid(parm,lwr+upr);}
function isAlphanum(parm) {return isValid(parm,lwr+upr+numb);}

function isEmail(str)
{
// enter with email address
		var at="@"
		var dot="."
		var lat=str.indexOf(at)
		var lstr=str.length
		var ldot=str.indexOf(dot)
		
		if (str.indexOf(at)==-1){
		   alert("Invalid E-mail ID\n\nMust have @ in address\n")
		   return false
		}

		if (str.indexOf(at)==-1 || str.indexOf(at)==0 || str.indexOf(at)==lstr){
		   alert("Invalid E-mail ID\n\nValid = abc@def.xyz")
		   return false
		}

		if (str.indexOf(dot)==-1 || str.indexOf(dot)==0 || str.indexOf(dot)==lstr){
		    alert("Invalid E-mail ID\n\nMust have '.' (dot) in address")
		    return false
		}

		 if (str.indexOf(at,(lat+1))!=-1){
		    alert("Invalid E-mail ID\n\nValid = abc@def.xyz")
		    return false
		 }

		 if (str.substring(lat-1,lat)==dot || str.substring(lat+1,lat+2)==dot){
		    alert("Invalid E-mail ID\n\nValid = abc@def.xyz")
		    return false
		 }

		 if (str.indexOf(dot,(lat+2))==-1){
		    alert("Invalid E-mail ID\n\nValid = abc@def.xyz")
		    return false
		 }
		
		 if (str.indexOf(" ")!=-1){
		    alert("Invalid E-mail ID\n\nSpace not allowed in Email address")
		    return false
		 }

 		 return true					
}


function Right(str, n)
{
if (n <= 0)
return "";
else if (n > String(str).length)
return str;
else
{
var iLen = String(str).length;
return String(str).substring(iLen, iLen - n);
}
}

function Left(str, n)
{
if (n <= 0)
return "";
else if (n > String(str).length)
return str;
else
return String(str).substring(0,n);
}