Added wxFrame::MakeModal for MSW, (it's already there for GTK)

git-svn-id: https://svn.wxwidgets.org/svn/wx/wxWidgets/trunk@2706 c3d73ce0-8a6f-49c7-b76d-6d57e0e08775

src/msw/frame.cpp

@@ -791,6 +791,20 @@ void wxFrame::IconizeChildFrames(bool bIconize)
     }
 }
 
+
+// make the window modal (all other windows unresponsive)
+void wxFrame::MakeModal(bool modal)
+{
+    if (modal) {
+        wxEnableTopLevelWindows(FALSE);
+        Enable(TRUE);           // keep this window enabled
+    }
+    else {
+        wxEnableTopLevelWindows(TRUE);
+    }
+}
+
+
 // ===========================================================================
 // message processing
 // ===========================================================================