How to update controls of startup form from another form?

Hi, I have a C# problem.

I created startup form as following:

Application.Run(new Form1());

Then I added on form toolstripstatus label   and one MY user control. I am doing some manipulation within this control and then based on this manipulation I want to update text of toolstripstatusLabel. But I have problem to access it.

Form1.toolstripstatuslabel1 does not work -

//An object reference is required for non-static field ///

Please, help me if possible. I was working in Visual Basic .Net, this is something new to me, even if maybe trivial...

Any help really needed. THanks

Zdeno