How to effectively use a timer for animation?

[niksh19]

Hello there.
My question is how can i use a timer function to animate a form's width being smoothly expanded and contracted on the click of a button

The resultant effect that i'm looking for is exactly what happens when you run windows native calculator

1.Windows + R key. Run: "Calc"
2. Change the views from View option between "Standard" and "Scientific".
Any ideas?

P.S - I've tried declaring two subs, using width += ## and width -= ##, but that doesnt output what i want, it just messes up things..