<!-- Script by hscripts.com -->
<script type="text/javascript">
function checkleapyear(datea)
{
       datea = parseInt(datea);
        if(datea%4 == 0)
        {
                if(datea%100 != 0)
                {
                        return true;
                }
                else
                {
                        if(datea%400 == 0)
                                return true;
                        else
                                return false;
                }
        }
return false;
}

function isLeapYear()
{
        var df = document.sd.yv.value;
        if(df!= "" && parseInt(df))
        {
                var res = checkleapyear(df);
                if(res)
                {
                 document.sd.val.style.color = "green";
                 document.sd.val.value = df+" is a leap year";
                }
                else
                {
                 document.sd.val.style.color = "#9a235d";
                 document.sd.val.value = df+" is  not a leap year";
          document.sd.val.value = df+" is  not a leap year";
                }
        }
        else
        {
                alert("Enter a proper value");
        }

return false;
}
function isInteger(s)
{
      var i;
	s = s.toString();
      for (i = 0; i < s.length; i++)
      {
         var c = s.charAt(i);
         if (isNaN(c)) 
	   {
		alert("Given value is not a number");
		return false;
	   }
      }
      return true;
}

</script>
<form name=sd method=post action="" onsubmit="return isLeapYear()">
Enter a year [ ex: 2020 ] - <input name=yv type=text onKeyup="isInteger(this.value)"><input type=submit value=go><br>
<input type=text name=val size=30 style="background-color:white; border:0px; margin:0px; color: #9a235d;" readonly>
</form>
<!-- Script by hscripts.com -->