How to programmically click the Minimize button in the Control box of a Form

I know this is probably a simple question but I don't know how to do it.

I have a form whose windowstate is set to minimized so that it will run minimized in the task bar.

When I click the Icon for this form it is restored. I click a button on my form which does some processing. When the processing is finished, I want to minimize the form back into the toolbar (with code) and not have to physically click Minimize in the control box.

What code should I use to programically click Minimize in the control box at the top of the form?