what is "ob_start();"......?

What is Google?
What is the PHP Manual?

I don't mean to sound condescending, but come on, if you had posted that question into a search engine, you'd have gotten all the answers you could have ever needed. An important part of being a programmer is the ability to research solutions, or at least the ability able to locate the reference manual entries for function calls in the language you are using. The first thing you should learn about a language is how to search it's documentation.

If you've already found the PHP docs for the function, and have more specific questions about the function that you couldn't figure out from them, please elaborate.

commented: exactly - and posting 'questions' with a title of php in the php forum doesn't show much ingenuity or clarity either :) +11