// JavaScript Document

function callback()
{
	if(document.form1.txtCallback.value=="")
	{
		alert("Mobile No. can not be empty.");
		document.form1.txtCallback.focus();
		return false;
	}
	if(isnumbers(document.form1.txtCallback.value))
	{
		alert("Invalid Mobile No. Only numbers are allowed");
		document.form1.txtCallback.focus();
		return false;
	}

}
function isnumbers(a,b){
	var iChars = "1234567890.";
  for (var i = 0; i < a.length; i++) {
  	if (iChars.indexOf(a.charAt(i)) == -1) {
  //	alert ("Invalid entry in " + b + ". Only numbers are allowed");
  	return true;
  	}
  }
}

var win = null;
function centerpopup(vpagen,wdth,hght){
if (win) {
win.close();
}
var winl = (screen.width - wdth) / 2;
var wint = (screen.height - hght) / 2;
 win = window.open(vpagen,"Nitco","toolbar=0,location=0,directories=0,status=0,menubar=0,scrollbars=no,height="+hght+",width="+wdth+",left="+winl+",top="+wint);
}