Thank you a lot for your support, guys.

@3dgs_snake Maybe a video card driver update will solve the problem?

@Nidhogg That's a strange error; I'll look into it. Concerning your idea: I have created a version that allowed the user to type in the amounts initially, but the client wanted it to behave this way. The "exit" and "help" buttons are great additions; if all works well I'll implement them in a future version of the program.

Please keep the feedback coming. Thank you.