add class="calculate" to your 4 textboxes
$('.calculate').on('keyup', function(){
var sum = 0;
$('.calculate').each(function(){
sum += parseFloat($(this).val());
});
if(sum>100){
alert('Sum is greater than 100')
}
if(sum<100){
alert('Sum is less than 100')
}
});
This solution requires
jQuery. If you don't use it yet, do something about it. Add this script ref in your document:
<script type="text/javascript" src="https://ajax.googleapis.com/ajax/libs/jquery/1.7.2/jquery.min.js"></script>
Submit an article or tip