Search Engines and iFrames

[EGS]

This has never came across my mind because I never use iFrames but I am going to have to for one of my sites. How do, or generally do search engines recognize iFrames? Can they read them or no? Do they spider them or recognize them as regular web page content?

Help is greatly appreciated because I'm deciding whether or not to use iFrames on my site.

 

[peter phillips]

I suppose the Search Engines can index the page referenced in the src attribute of the IFrame, but it is indexed as a seperate page not as a part of the page the iframe is on.