Calculate user input

Question

Hi, guys:
I have a challenging problem for me. I have two
input fields (nested:text tags) for user to enter
item number and cost, then calculate the total cost.
Total cost should be displayed automatically after user
enters item number and unit cost.
I know this will be done in
javascript, but I don't know where to look. If you
guys know how to do this in Struts, please let me know.
regards

Answer 1

I'm not sure i understand your question but in javascript it could look like that:
<script language="javascript">
function calculateTotal() {
//you should add some code to check for null values or empty string
cost = document.forms[0].cost.value;
qty = document.forms[0].qty.value;
result = cost * qty;
document.forms[0].result.value = result;
</script>
<form>
<input type="text" name="cost" onchange="calculateTotal()"><br>
<input type="text" name="qty" onchange="calculateTotal()"><br>
<input type="text" name="result"><br>
</form>