Read Javascript value into PHP variable?

[vikinggirl***]

Hi all
I want to get a value using javascript and read it into a php variable.
I am not sure how this is done.

The value I want to get is the Current Document Height

I then want to read that value into a php variable called $current_height.

(After I've got the value in php, I'll write an easy  if ... then statement based on the value. )

I think the javascript for getting current document height is

[CODE]

expression(document.all.getElementByID('left-sidebar').style.height

[/CODE]

Or something like that. Cannot check until I know how to read it into a variable anyway.

Please can you help me with the syntax for reading this javascript into the variable?

Best
Jo

[Barand]

Bearing in mind that javascript is running on the client and PHP runs on the server, the easiest way is to put the js value into the value of a hidden form field so it gets submitted with the rest of the form data.

[trq]

Because Javascript runs on the client and php on the server, you'd need to submit the data to a new php page. This could be done a few ways, but the neatest would probably be to use a little ajax trickery.

[url=http://marc.theaimsgroup.com/?l=php-general&m=112198633625636&w=2]Here[/url] is a simple tutorial written by the creator of php himself.

Hope it helps.