Date: Sep 18, 2012 3:53 AM
Author: Dr.J
Subject: set option flag in function definition

Dear Experts,

I had one question regarding to the function definition.

I want to have a function that executes certain operation when I chose the
corresponding option flag.

For example,

a function called "f"

when I call it like f[arg1,arg2,arg3, optionX]
it executes command

If I call it like f[arg1,arg2,arg3,optionY]
it executes command

If I call it like f[arg1,arg2,arg3,optionSomethingElse]
it returns me
"No appropriate option flag was found. Please indicate correct options"

This looks a bit like scripts running in UNIX. I am wondering if I can do
the same in Mathematica easily?

Thank you so much for your kind help!