When you select Edit Program from the PROGMAKE Facilities menu focus moves to the Program entry field. Do one of the following:
Create a new program by entering a name that is not currently used (see below for how to find out which have been). QAB will create an empty program having that name, which you can edit.
Enter the name of an existing program
Press <Ctrl+P> or click on the Prompt button for a menu of existing programs, like the one shown below:

You can select one by double clicking on it or by using the arrowed cursor keys to highlight the required program and then pressing <Enter>.
In all three cases once you have chosen the program to work on you will be taken to the Program Editing Functions menu.