add two text boxes and display in another textbox

superdan_35

Hi all.

I have a form with 5 text boxes for the user to enter numbers. I would like to have a sixth text box at the end that adds up the total of all the other inputs.

I assume that this can be done and will require javascripting or AJAX, but is there a way to do it using php?

Thanks,
Dan

djjjozsi

if you reload the page you can use the php + operator to add their values into one.
this is the easiest way.

<?php
$sixth= $_POST["f1"]+$_POST["f2"]+$_POST["f3"];
?>

Total: <input name="sixth" type="type" value="<?php  echo (empty($sixth)?0:$sixth) ;  ?>">

superdan_35

Thanks. So to reload the page could I put an onChange event in the first 5 textboxes so when the user enters a new number the page would reload and change the total? Or would this cause problems, such as losing input?

Dan

khaine

I would avoid using the onchange event to submit. This will fire alter every keystroke which would be very annoying if it is submitting on every key press. onBlur may be a better one to use. So the calculation is triggered when the user exits the box.

If you do use a PHP solution you can return the values submitted back to the input box via the value="" entry in the tag.

Javascript from the onchange event would be my choice. If you are not up on javascript try the prototype library. It makes things much easier and deals with browser differences.