usage of the LoadFileDlg

I was trying to us the LoadFileDlg box on the main screen of the example when the screen stopped refreshing. And when I canceled the dialog, the game froze.

the script looks like...

new GuiButtonCtrl() {
profile = "GuiButtonProfile";
horizSizing = "right";
vertSizing = "top";
position = "29 264";
extent = "110 20";
minExtent = "8 8";
visible = "1";
command = "Canvas.setContent(LoadFileDlg);";
helpTag = "0";
text = "Load Game...";
};

is there something that I'm missing?