Using document.onkeyup to calculate a field value

[kodt]

I have a form with 4 text input fields. The last one is the total of the previous three fields and should automatically calculate this value when a user enters data into any of the first 3.

Normally I would put an onkeyup="" event on the input elements and have that call the function. However, this form is automatically generated based upon information in an XML file. I can add some HTML and Javascript to the page via the XML file, but cannot directly modify the form elements. I am wondering if there is a way to run the calcIT() function below on every onkeyup event. The code below does not seem to be working. I know the calcIT function works correctly.

document.onkeyup = calcIT(document.quizform.userans0.value, document.quizform.userans1.value, document.quizform.userans2.value);
 
function calcIT(v,a,b) {
 
var total, v2, a2, b2;
v2 = parseFloat(v)
a2 = parseFloat(a)
b2 = parseFloat(b)
total = (v2 + a2 + b2);
 
document.quizform.userans3.value = total;
 
}

[acoder]

Welcome to TSDN!

Put the call to calcIt into another function, say calcNow, and then call:

window.onkeyup=calcNow;

[kodt]

Welcome to TSDN!

Put the call to calcIt into another function, say calcNow, and then call:

window.onkeyup=calcNow;

This does not appear to work either. Below is my updated code. I also tried putting an alert box in calcNow for testing, and it did not show up. Thanks.

window.onkeyup=calcNow;
 
function calcNow {
calcIT(document.quizform.userans0.value, document.quizform.userans1.value, document.quizform.userans2.value);
}
 
function calcIT(v,a,b) {
 
var total, v2, a2, b2;
v2 = parseFloat(v)
a2 = parseFloat(a)
b2 = parseFloat(b)
total = (v2 + a2 + b2);
 
document.quizform.userans3.value = total;
 
}

[acoder]

You forgot the parentheses on line 3:

function calcNow() {

[kodt]

You forgot the parentheses on line 3:

function calcNow() {

Thanks that worked.

I find that most of my javascript errors are syntax errors that I overlook :\

[gits]

Thanks that worked.

I find that most of my javascript errors are syntax errors that I overlook :\

... to avoid it you may use an editor that checks such things (personally i use eclipse with the jseclipse-plugin) ... or to find that errors you may use the firebug-extension for firefox ... really good tools for js-development ...

kind regards ...

[kodt]

Replaced window.onkeyup with the following code to work in IE.

window.onload = function() {
document.getElementById('userans0').onkeyup = calcNow;
document.getElementById('userans1').onkeyup = calcNow;
document.getElementById('userans2').onkeyup = calcNow;
}