HP 3000 Manuals HP 3000 Manuals
Functions Functions are similar to subroutines in a conventional programming language. When a function ends, control returns to the item that called the function. Functions use the same constructs, and generally the same commands, as processes. The function you are about to create is executed by the screen logic as an after function for a field on the screen. This means that it is executed after the user enters data to the screen field. Functions can also be called from a function key or through a VISIT command in any logic block, as well as a number of other methods. It's important to remember that a function does not alter the application environment when it's called. Developing a function is similar to developing a process. You must define the header first, and then the details. A function must be generated before the application can use it. Every logic command except the MODE command can be used in a function. The MODE command is only permitted in a process.