Too bad you don't provide your sourcecode so that helpers can see whats going on there.
And you don't really explain what you are doing. So i can just guess that you don't use the php mysql_error() function
MySQL errors will not be displayed automatically. You have to program its output by yourself.
P.S.: It would be polite to start your threads with some sort of greeting and end it with a complimentary close. It doesn't cost that much time compared with the time a helper efforts to try to solve your problems.