But if i write : GSTNet_HTTPGet("http://www.littlesubmarine.bplaced.net","/test.php",serveripserver);

the standard ipnumber(000.000.000.000) doesnt change to the servers ip and the game chrashes

Have you tried "littlesubmarine.bplaced.net" ? the www doesn't really have a meaning.

SchokoKeks is right! It should be "http://littlesubmarine.bplaced.net"

for lite-c use
GSTNet_HTTPGet(_str("littlesubmarine.bplaced.net"),_str("/test.php"),sResult);

for c-script use
GSTNet_HTTPGet("littlesubmarine.bplaced.net","/test.php",sResult);

thanks nfs 42

P.S. What do i have to write that the client sends its position to the server and the server sends it to the other clients. I used GSTNet_TrackEntity(player,1+2); Something wrong or do I have to add more lines of code ?

Hello.
I have question.
Why i cant join server in local network with external IP.
Im not tested it from other networks, but dont sounds too nice.

Is the port open ? (portforwarding)

try http://portforward.com/ if you doesn't know how forwarding works with your router.
you have to open the chosen UDP port.

ou. True true it could be my problem. I will check it.