The function below is your javascript, put this between your HEAD tags on your page. It simply takes the 'units' box on your form and multiplies it by the 'rate box'. Then it displays the result in the 'total' box. if you want to change it to addition, just change the line of code to
var Total = Units + Rate etc...
Below that is the form already set up to run the function when you change a value in the boxes
<script javascript>
function DoMath(){
var Units = document.frmData.Units.value
var Rate = document.frmData.Rate.value
var Total = Units * Rate
document.frmData.Total.value = Total
}
</script>
<body>
<form name="frmData" method="POST" >
Units:<br>
<input type="text" onchange="DoMath()" name="Units" size="20"></p>
<p>Rate:<br>
<input type="text" onchange="DoMath()" name="Rate" size="20"></p>
<p>Total:<br>
<input type="text" name="Total" size="20"><br>
<input type="button" onclick="DoMath()" value="Update" name="B1"><input type="reset" value="Reset" name="B2"></p>
</form>
</body> |
