[thelist] php question - changing one form value based on select choice

Erik Mattheis gozz at gozz.com
Mon Oct 17 20:40:28 CDT 2005

You would do this with JavaScript, but  it would be much wiser to come 
up with $price on the fly in your form processing template.

To do it with JavaScript, (if you must):

function changePrice(form) {
   if(form.Size.options[form.menu.selectedIndex].value == 'Large') {
     form.hiddenprice.value = 10;
   else if(form.Size.options[form.menu.selectedIndex].value == 'Small') {
     form.hiddenprice.value = 8;

<select name="Size" onchange="changePrice(this.form)>
  <option value"Large" selected="selected">Large</option>
  <option value"Small">Small</option>
<input type="hidden" name="hiddenprice" value="10" />

To do  it server-side with PHP, just set up a conditional that assigns 
the correct value to $price based on the value of $_FORM['Size'].

On Monday, October 17, 2005, at 08:04 PM, Jeniffer C. Johnson wrote:

> I think this might possible, but can't think of how to do it (and 
> can't find
> an accurate search phrase). What I want is to have a form with a select
> list, and based on which option is selected, to send a specific hidden 
> value
> with the other values when the form is submitted. So if, for example, 
> Large
> is selected from the Size list, then a hidden field giving price of 
> $10 is
> sent, but if Small is selected, then the hidden field is sent assigning
> price of $8.00.

- Erik Mattheis
612 377 2272

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