x server + glut

Hello,

I am using glut library on Linux.

When the window is created with glutCreateWindow, it will return an id, 
which doesn't corresponds to the x-server window id. For example, this 
command returns 1, and xwininfo (ran from the shell) returns something 
like 0x4800002

Is there a way to get the x window id in c?

Thanks in advance?