>>Look at the switch command
>
>Switch will not help me in this case as I need 3 cases:
>
>Both variables defined
>
>startTime defined
>
>endTime defined
>
>I don't see how switch can help - switch is only for checking a single variable against predefined values.

That's the problem.... if its not in a blog post, you can't figure it out....Learn to think outside a blog post...