open with url

[jwk811]

xmlhttp.open("POST", 'lib/sendMessage.php', true);

 

the url needs to change on every page. that will work for just the home page.

other pages would need ../lib/sendMessage.php because they are in different folders.

 

how can i make it so it works no matter what page they are on.

i tried putting the domain like http://www.domain.com/lib/sendMessage.php but that does not work!

 

i thought i could use my web root from my php function and <?php  echo WEB_ROOT; ?> but that wont work. there has got to be a way and i want it so you dont have to type in the url and it gets the url itself like my web_root function does so it can be used with different websites

 

PLEASE HELP!!