"interaction" between two from

[yamaha102]

Instead of assigning your new Form2 instance to a local variable, i.e. one declared inside a method, you need to assign it to a member variable, i.e. one declared outside all methods and therefore available to all. You can then handle the ValueChanged event of the TrackBar in Form1 and call the method that you declared in Form2 using that member variable.

i'm sorry. i am getting confused.