cardValid.html

﻿<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "https://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
<html xmlns="https://www.w3.org/1999/xhtml">
<head runat="server">
    <title>Card Validator</title>

    <script type="text/javascript">
 
 function check()
    {
        var no = document.getElementById("no").value;
        if( no != "" )
        {
          if(no != undefined && validate(no))
          {
              window.alert("The Entered Card Is Valid");
          }
          else
          {
              window.alert("Card Number Invalid !!!!!");
          }
        }
        else
        {
          alert('Please enter your card number');
        }
    }
    function validate(num)
    {
        var result = false;
        var numArray = new Array();
        numArray = num.split('');
        var sum=0;
        for(var i = 0; i< numArray.length; i += 2)
        {
           numArray[i] = numArray[i]*2;
           if(numArray[i] >= 10)
           {
              var temp = new Array();
              temp = numArray[i].toString().split('');
              sum = sum + parseInt(temp[0]) + parseInt(temp[1]);  
           }
           else
           {
                sum = sum + parseInt(numArray[i]);
           }
           sum = sum + parseInt(numArray[i+1]);
        }
        if(sum % 10 === 0)
        {
            result = true;
        }
        return result;
        		
    }
    </script>

</head>
<body>
    <form id="form1" runat="server">
    <div>
        No<input type="text" id="no" />
        <button type="submit" onclick="check();return false">
            check</button>
    </div>
    </form>
</body>
</html>