Debug assertion failed while debug the application

[PandyaChinna]

I have created one sample mfc application with listcontrol and button.while clicking the button new window should open that also have done.now that new dialog box i created new class and one function .on that function i am trying to insert items into new dialogbox list control.function calling was happening but error is like debug assertion failed.

[Thomas1965]

You need to provide more information. If an assertion fails it means that you probably called a function with wrong parameters.

What's the message?
You also need to show the function where the problem is.