php/mySQL not communicating- mySQL error (?)

I have several forms on different pages that are all supposed to enter data into only a few fields of a big table (like 6 out of 40) each. Near as I can tell, my php code is correct (using update query) to enter the data into a record based on the user name (as in Update Tablename bla bla where username='$username'). But I'm having trouble pre-creating the usernames in the table using phpmyadmin. I have all the fields listed as type TEXT, or should they be CHAR or VARCHAR or something else? Thanks again, Jeof Oyster PS- Please hit "reply to all"