Calling functions on the default form

I've managed to fix this now, I'll post the solution so it's archived. In the Program.cs file which launches the first form the default line reads as follows: Application.Run(new Form1()); What I did was set a static variable at the top of the Program class like this: public static Form1 mainForm; and then changed the run line to be as follows: Application.Run(mainForm); Functions on this form can then be called by referring to mainForm, for example: Program.mainForm.publicFunction(); I'm sure there are neater ways (and I'd love to hear them) to do this but this does work! Ian.