I am doing a windows forms application in Visual Studio 2005. I have all the forms, as well as some additional classes in source files for data storage. I was wondering how to update data in one class based on another class. Does this need to be done through a virtual superclass, or what is the best way to do this?

For Example, "form1" calls a function in "OneClass", which calls a function in "AnotherClass". When I try to update members of "AnotherClass", I get a null reference exeception. Thanks.

The error is because somewhere in there you are trying to dereference a pointer whose value is NULL.

Without examples of OneClass and AnotherClass and exactly what method(s) you are calling to cause the error I cannot help further.