Excel's Formula - sisman

620
Part VI: Developing Custom Worksheet Functions
Using the Insert Function Dialog Box
Excel’s Insert Function dialog box is a handy tool that enables you to choose a particular worksheet
function from a list of available functions. The Insert Function dialog box also displays a list
of your custom worksheet functions and prompts you for the function’s arguments.
Custom Function procedures defined with the Private keyword don’t appear in the
Insert Function dialog box. Declaring a function as Private is useful if you create functions
that are intended to be used by other VBA procedures rather than in a formula.
By default, custom functions are listed under the User Defined category, but you can have them
appear under a different category. You also can add some text that describes the function.
Adding a function description
When you select one of Excel’s built-in functions in the Insert Function dialog box, a brief
description of the function appears (see Figure 23-3). You may want to provide such a description
for the custom functions that you create.
Figure 23-3: Excel’s Insert Function dialog box displays a brief description of the selected function.
If you don’t provide a description for your custom function, the Insert Function dialog
box displays the following text: No help available.
The following steps describe how to provide a description for a custom function:
1. Create your function in the VB Editor.
2. Activate Excel and choose Developer➜Code➜Macros (or press Alt+F8).
The Macro dialog box lists available Sub procedures but not functions.