Replacing a special character

I have this form that people use to add entries into a MySQL database. Recently I've had some users insert − in their entries instead of - which is causing some issues with scripts down the line. I'd like to replace the − character with -. Originally I had something like $name = mysql_escape_string($_POST["name"]); which would convert the offending character to − before entering it into the database. It's this encoding that is causing the problems since some scripts send out emails with this entry in their subject line which looks messy. I've tried adding the following line after the previous line to help fix this issue, however, I just got another entry with the same problem. preg_replace('/−/','-',$name); Any suggestions on how others would fix this problem? I'd just like to fix it before the entry hits the database instead of creating fixes on the other end of things. Cheers, Michael