can i use <iframe> tag to display ads. As when my account is disabled to some accident clicks or anything else, it will be easy to remove the adsense code immediately
Depending upon what you are using, you could just include the ad-code with a <!--#include virtual="/adcode.html"--> statement in your html. There are varieties of that that can be used for other situations, but I find the #include the easiest for my particular situation. I think you can use an IFRAME, but be careful of getting non-relevant ads. See here: https://www.google.com/adsense/support/bin/answer.py?answer=10035&ctx=en:contact Specifically:
it would not be a good idea to use adsense on iFrame. since the iFrame page itself will not have any content, you will not get targeted ads. if you want to use a common page for adsense and dont want to code each page for adsense, then best way to do it will be by using PHP include or SSI (server side include). you can google for these term to learn more