Test for type of frame

First, a little background: I've been AppleScripting QuarkXPress for about 12 years and some tasks, such as displaying a page in a document, seemed much easier to script in QuarkXPress, so please forgive my "newbie" questions and status with InDesign. We just switched our production department to InDesign, from QuarkXPress, and now I have the task of rewriting all of the old QuarkXPress scripts.

Here's the (current) issue: I want to add a little error checking to my AppleScript to determine if a frame is a text frame. Unfortunately, I cannot figure out any way to execute that test.

Any and all help, as well as possible resources for scripting InDesign, would be greatly appreciated.