Ok. I will try to ignore the fact that you provided way too much code that seems very cryptic and unreadable, while only about 10 lines are related to the error... I will ignore the fact that most of the infrotmation you provided with your code is absolutely useless and irrelevant. I will ignore the fact that the title of your first post is the second worst possible title (the first one being "PLZ HELP URGNT"). And I will also try to ignore the fact that your last post didn't contain that mysterious word starting with "tha" and ending with "nks"... If my previous advice didn't help, there is not much more I can do for you. The best help I can give you is: Read the compiler error carefully. Locate the problem in your code. Check everything on that line, see what parameters are required for each method... And then make sure that the parameters you are passing match the required type. With intellisense and all the support provided by Visual Studio (or whatever tool you use) it should not take more than 23.7865039 seconds to locate and fix such a simple error like a type mismatch... even if you are a beginner!

Not a database related question, more a C# question. What you need to do is Handle the TextChanged or ValueChanged event of the ComboBox. In the event handler, populate the ListBox with the required data from your database etc. Steve Jowett ------------------------- Real Programmers don't need comments -- the code is obvious.