Shortcut key: F8 Use the Trace Into command to single-step through your program, entering each function when it is called. When you reach a function call, Trace Into (F8) steps from the statement that calls the function to the first executable statement in the function. You can then debug the function in the same manner. Once you have verified that the function works as designed, use the Step Over command (F10) to save time as you continue debugging.