CompuServe Messages

Hi Tony, could you answer a question for me please? I often find it benificial to look at someone else's lisp routine to get an answer to my questions or problems, but this has me puzzled. Looking over some of the sample routines included with ACAD I find "secondary" functions (for lack of a better term) built inside the main fuction. Some Error fuctions seem to be common examples. They are nested inside the main fuction. Other times it may be a "sub-function" or a branch routine. Is there a reason for this that I am missing? Is there pros or cons for doing this or not doing it? I haven't found anything about it in any of the books I have acquired (or I haven't found it at least). Would appreciate your comments or advice. Thanks! Phil