How To Get Complete Url Using Php

can you send me the function that you use for getting the complete url from a page using php?

like for example, this thread that i am staring i want to be able to get the full url like this: http://www.webune.com/forums/how-to-get-complete-url-using-php.html

if i use php_self, it only gives me this: /forums/how-to-get-complete-url-using-php.html

i know you sent it once, but i lost it and i need to use it.

or if you can point me to your library of functions and classes please