Using 'invalidate' for the first time

[ready2drum]

I have a program that draws brackets on the screen to indicate the far left position and far right position of a car. The brackets appear on the screen when a user selects 'show limits' from the drop down menu of the program. I'd like the brackets to disappear from the screen when a user unselects the drop down menu item, 'show limits'. I was instructed to use the 'Invalidate' method to force the screen to be redrawn so that the brackets will disappear. I've never used the 'Invalidate' command/method before.

Any suggestions or advice on where in the program code it would go?

Thanks for your advice, comments, suggestions, and or help!

[Bazzy]

I think that is the flag you have to use in the RedrawWindow function

RedrawWindow(/*Window Handle*/,0,0,RDW_INVALIDATE);