Live Demo: Even Odd in javascript

<html>
    <body>
        <script>
            function EvenOdd()
            {
              var a=prompt("enter a number:");
	      if(a%2==0)
                   document.write(a+" is Even number");
              else
		   document.write(a+" is odd number");
	     }
        </script>
        <form>
            <input type="button" value="EvenOdd" onclick="EvenOdd();">
        </form>
    </body>
</html>