Calling system from clickon processor

[Bill Czermak <czermak netspace net au>]

Am new to GTK+ 2.4  (Although I did try GTK 2 years ago.  Glad to see 
that features I did not like are now depreciated

Have written basic menu program to display buttons to select firefox, OO etc

Clickon code is:

void office(GtkWidget *widget,gpointer data){
   system("openoffice -writer &");
   }

When I run under a gnome login, programs load OK, but if I load several 
instances, when I exit one instance, all instances exit.

Could anyone explain what I am doing wrong.  Cant find any pointers in 
GTK doc as to how to start a program from a GTK program.

Thanks in advance

Bill C