[RESOLVED] onkeyup

[andersstudio]

Hey,

I would like to perform a calculation as soon as the user leaves the textbox and output the answer in another field.

Here is what I tried:

<input type="text" onKeyUp="return autoTab(this, 2, event);" name="bbq" size="2" maxlength="2">
<?php
$bbqnum = $_POST['bbq'];
$bbqttl = ($bbqnum * 15);
?>
<?php print $bbqttl; ?>
</input>

Thx!

[devinemke]

i think you are getting confused between client-side and server-side programming. javascript runs on the client. PHP runs on the server. your code is calling a javascript fucntion that will be excuted solely on the client, before anything is sent to/received from the server.

[leatherback]

Yeah,

You can, but need to use only javascript (See devinemke's response)

You need to use something like:

function calculate()
{
var calculated = 0;
var value = document.FORMNAME.FIELDNAME.value;
calculated = 10*value;
document.getElementById('RETURNFIELDNAME').innerHTML = calculated;
}

where:

<span id="RETURNFIELDNAME"></span>

will show the calculated value.

[andersstudio]

Hey,

I originally used javascript, but I didn't use the innerHtml that you used. I also did not know how to return the calculation in an output field, which is why i turned to php. I thought there was a way to call the php without hitting submit.

Sorry for the trouble. This works great.

I'm going to look up the explanation of the following line of code that I do not understand:

document.getElementById('output').innerHTML = calculated;

thx

[leatherback]

Hi Anders,

It basically tells the browser to insert HTML in the ELEMENT which has ID = 'output' , and the HTML should be: THe value of calculated

J.

[andersstudio]

Ok, I understand and have everything working.

However, how do I go about pulling the span id value into php?

I tried pulling the span id value inot a hidden field before using
$total = $HTTP_POST_VARS['total'];
to pull in the value, but my javascript code must not be right.

<span id="total"></span>
<input type="hidden" id="total" value="<script language='JavaScript' type='text/javascript'>document.form.total.value;">

[leatherback]

Hi,

For that, you would probably have to do it like this:

function calculate()
{
var calculated = 0;
var value = document.FORMNAME.FIELDNAME.value;
calculated = 10*value;
document.getElementById('RETURNFIELDNAME').value = calculated;
}

and

<input type="hidden" id="total">

but I am not sure whether this would work.

I would personally do the math again in PhP, based on the values that were filled out by the user. Javascript is ignored by certain browser / usersettings..

J.