I am encountering a problem regarding URL rewriting. I am using Apache\'s mod rewrite to rewrite URLs. For example, I rewrite URL
www.website.com/some/path/
I suggest (as mario) to take a look into the QSA flag (Query String Append). Additionally I would take the question-mark out of the character class in the regex:
RewriteRule ^([a-z_/]+)$ request.php?string=$1 [L,QSA]