u2orange, thank you so very much for helping me!
However, what I need is a little different. The program contains a prompt box as a confirm method. So the program assumes that the user presses ok in the prompt box. However, I would like to have an if statement that will have an alert box with an error message, if the user presses "cancel" instead of "ok" for the prompt.

Thank you again very much for your time and willingness to help.