void addWindowSubclass() {
long /*int*/ hwndChild = OS.GetWindow(browser.handle, OS.GW_CHILD);
if (SubclassProc == null) {
SubclassProc = new Callback(MozillaDelegate.class, "windowProc", 4); // $NON-NLS-1$
MozillaProc = OS.GetWindowLongPtr(hwndChild, OS.GWL_WNDPROC);
}
OS.SetWindowLongPtr(hwndChild, OS.GWL_WNDPROC, SubclassProc.getAddress());
}
static {
menuItemSelectedFunc = new Callback(ToolBar.class, "MenuItemSelectedProc", 2);
if (menuItemSelectedFunc.getAddress() == 0) SWT.error(SWT.ERROR_NO_MORE_CALLBACKS);
}