Dreamweaver的SQL代码无法正常工作

Dreamweaver generated som sql-code that's not working. I believe this is where the error originates from:

$insertSQL = sprintf("INSERT INTO gjestebok (tidsstempel, tittel, navn, tekst) VALUES (NOW(), (%s, %s, %s)",
                   GetSQLValueString($_POST['tittel'], "text"),
                   GetSQLValueString($_POST['navn'], "text"),
                   GetSQLValueString($_POST['tekst'], "text"));

When I try to insert it into my database it shows me this message:

You have an error in your SQL syntax; check the manual that corresponds to your MySQL server version for the right syntax to use near '' at line 1

Can someone spot the error?

Edit: Found the mistake. It was the "(" in front of the first "%s" I had to remove.