Okay so, what I need to achieve is a button that allows the user to click two different locations in a picturebox and can create a straight line, just like in Microsoft Paint.
This is for my Major project due on the 17th June 2013 for Software and am unable to find any other discussions to help me.
Would any of you be able to help, please?

What have you attempted? What resource materials have you read? Here's a thread with some info that should help.