Determining if a variable is blank.

I have a simplistic forum, and I am trying to write some code to determine if the message box actually contains information, because if it is blank I obviously don't want to post it to the database. The message box has the name of 'reply'. Here is the code I'm trying to use, but its not working: $reply2 = str_replace(" ","",$reply); if(empty($reply2)){ // echo some error message to the user that they can't post a blank message } else{ // post the message } This however didn't work for me. So I had the thought that maybe the variable $reply2 isn't set because it is blank. So I tried this: $reply2 = str_replace(" ","",$reply); if(empty($reply2) || !isset($reply2)){ // echo an error message } else{ // post the message. } I've tried different variations on this same idea, but somehow none of them are working. Can anyone give me any suggestions or insight? Jason Cathcart Check Out My Site: http://www.biohazardous.org