Hello: I just bought this maple sofware last week, and I need some help with that. I am tryingto do my homework from college, "calculus and trig" I need to know how I can erase after I have bee done an exercise in the little window going to: maple 11, untitle, tools, tutor, single variable? I this is very good but I jsut can not erase anyting after I did an exercise , please I need help!! thank you!