ereg-replace removing whitespace...

Hi... I'm trying to use ereg_replace to replace "[/URUB]" with "</strong><br />" The problem is that ther might, and might not, be any number of trailing whitespaces after the [/URUB]-tag... Everything between the [/URUB] (and the tag itself) and the next alphanumeric char should be replaced with "<strong><br />" So far I use: $str = ereg_replace("(\[/URUB\])+( |\n|\t|\r)*","</strong><br />",$str); which doesn't work, leaving a lot of whitespaces behind... Thanks for your help... .bobo