RewriteRule REGEX ?

My server runs Apache 2.0. I am trying to do a simple URL rewrite so that old URLs will map to our new style of URLS... From This: articles.php?id=999 To This: articles/999 In the .htaccess file for the htdocs folder that contains the web files, I put the following: RewriteEngine on RewriteRule ^articles\.php\?id=([0-9]+)$ articles/$1 [R] I've also tried this (no slash in front of ?): RewriteEngine on RewriteRule ^articles\.php?id=([0-9]+)$ articles/$1 [R] But I keep getting a 404 error for articles.php, which means that something must be wrong with my RewriteRule because it's not matching. I've tried various tweaks and just can't get it to work. What am I doing wrong?? Thanks.