evenorodd.html

<html>
<body>
    <script type="text/javascript">
    function evenorodd()
    {
    var num=document.getElementById('bb')
    "<br>"
      if (num.value=="")
 {
        alert("enter a value")
    }  
    else
    { 
    if (isNaN(num.value))
{
    document.write("Enter only numbers. Not strings")
}
else
{
        document.write("Number:" +num.value+"<br>")       
        if (num.value%2==0)
        {
        document.write("Even number")}
        else
        {
             document.write("odd number")}
    }}
    }
    </script>

<form name="aa" method="get" align="center">
    <br><br>
Enter a number:<input type="text" value="" id="bb" size="5">
<br>
<input type="button" value="Evaluate" onclick="evenorodd()">&nbsp
<input type="reset" value="Reset">
</form>
</body>
</html>