I Have google adwords on my website and i am currently redesigning it big time and i was just wondering if i could put the same ad into 100's of pages or do i have to get seperate code for each page???
yes sorry its ad sense
cheer for that

You use the same general code that you have – you don't have to apply again to Google Adsense.

However, to make it easy for you to track how your pages are performing, especially those of the same topic, I suggest you learn about CHANNELs and how to use it. With channels, you can group your pages together by topic or whatever configuration you like, or even create channels for specific pages (e.g. a separate channel for the homepage). You can also create a separate channel by ad format — e.g. medium rectangle, skyscrapers, etc — so you can find out the best ad position and format to use.

Channels are great for learning which pages or topics bring in the most revenue, or which gives you the best click through. The information can make it easier for you to configure each page if a page is not performing as well as you expected.

You can learn about Channels from the Adsense Help pages