SQL/PHP problem

I'm trying to delete rows from a database where the date is older then my $expDate variable, but for some reason, no matter what I try and what examples I use for help, I can't get this to work??? I first took the $expDate string and set the var type to "integer". The datatype for the "msgCreated" field is "int". I first tried: $sql = "DELETE * FROM Table WHERE msgCreated < '$expDate'"; and it didn't work so I then tried it without the single quotes: $sql = "DELETE * FROM Table WHERE msgCreated < $expDate"; still, it didn't work. Am I missing something fundamental here? Is this one of those RTFM questions? Thanks, Brian