Randomization in PHP

I'm writing a game in PHP. Now the script generates a random number to get the players registered. But: the number generated is the same for every player. It's about this line:

$activationkey = rand( 1000000000, 9999999999 );

Every player gets the same key. How can this be? Any help? Thanks you

Leon

Top 10 Countries APIs

Developers wishing to create applications supplied with data about individual countries and other international data may be interested in these APIs found in the Countries category of ProgrammableWeb.

What is a Countries API?

A Countries API, or Application Programming Interface, is an interface that connects developers to software featuring data concerning countries around the world.