gtk::timeout_add
int gtk::timeout_add(int interval, 
      GtkFunction 
      function
     , [mixed 
      data
     ]); 
    
     Registers function to be called periodically. 
     The function will be called repeatedly after interval
     milliseconds while it returns TRUE. When
     function no longer returns TRUE 
     the timeout is destroyed and will not be called again.
    
    
     You should save the returned number if you want to
     gtk::timeout_remove()  it.