to those who welcome new guys to js and would be happy to help!

I am trying to create a Grease Monkey script that would add a GET variable to the source of objects that result in new http requests when a webpage is loaded in browser, I mainly mean the css, img, js, and if possible the flash files. I searched the web and found lots of codes that would completely change the src of an img but didn't get a clue how to add a string to the src. it seems to me it isn't a complicated job. is it? if so images are come first the others aren't as necessary.

here's the illustration
src=X --> src=X?parameter=value
"?parameter=value" added to X.