Change Display !!!

["Anil Kumar P - Roll No.98002" <anil gdit iiit net>]

Hello !!!

        How can i change display within my GTK program. 

        I have a GTK program which takes screenshot and saves it as a
jpg file. If i wanna capture the screen of other computers running xserver
with xhost enabled, i simply export the environment variable DISPLAY to
the screen i am interested. Now i want to develop a GUI which takes
multiple addresses and displays their respective screenshots on the GUI. 
(notebook).