IBM's Learning PHP Part 1 tutorial.

Newbie question. I'm working my way through IBM's PHP tutorial. Generally good ... but I'm stuck at an error point and have no idea what's going wrong. Before adding a new row to the mysql database (already opened) we do a query to see if a particular record already exists. (see $resultT). We then test, using if, to see if $resultT is true or false. If it's false we are then supposed to enter a new record. Problem: it's never false. It always evaluates true. What am I doing wrong? TIA /* build query to see if the record is entered already */

    $sqlT = "select * from users where username='".$_POST["name"]."'";
    $resultT = mysql_query($sqlT);

/* Now test -- did we find anything ... if not add this user */

    if (! $resultT) {

/* here we add the new record if it doesn't already exit /*