PHP $ GET function in .HTM document

There is a dialog and it has: "image.htm?src="

[CoolJRT2009]

Hi.
Here.
There is an image editing dialog box that is in Zoomshare. It has a code I am trying to find.
It uses the PHP $_GET function there (?src=), but I can't find it and don't know how to get it in a HTM document. Please help if you can.
Thanks.
From Hayden :)

[coopster]

PHP's $_GET variable is a superglobal array that can be accessed and used on the server to work with user-supplied data in the GET query string.

[g1smd]

You'll need to tell your server to process files ending in .htm as being files that can contain PHP scripting. That's a one-line entry in the .htaccess file.