Qx: Update/Delete MSAccess thru ODBC

Please help me.
I am now using PHP to connect MS Access database thru ODBC. Data retrivial is ok but error is found in UPDATE and DELETE. Is anyone of you have problem as same as mine? How to deal with that?
The code is:

The error message is:
Warning: SQL error: [Microsoft][ODBC Microsoft Access Driver] Must use update query., SQL state S1000 in SQLExecDirect in E:\php\save.php on line 13

the link is:
http://www.ympoon.com/php/userdb.php
Please help me.