Hi,

Your problem is that you are searching for something that doesn't exist. The content you printed clearly shows there is no "iframe" string in the text. So you can search that text all you want for "iframe"--using Mechanize or anything else--and you are never going to find it.

The reason the actual page's text has "iframe" in it is presumably because the browser reads that text you have, and the browser sees some javascript code in there, so the browser executes the javascript code. Then somewhere in the javascript code there are instructions for the browser to add "iframe" to the text, which it does producing a new page of text.

Therefore, in order to find the "iframe" text you want, you need to give the text you currently have to some kind of program that can read the text, recognize the javascript, execute it, and produce a new page of text according to the instructions in the javascript. A few years ago there were no such programs that could do that because they were too difficult to write. Now apparently there are some.