Visio Guy

hi,
In My program, I use ActiveX controls to display Visio graphics. After opening the file, I use the following code to close the Shape Search Window.
mCtl.Window.Application.ActiveWindow.Windows.get_ItemFromID((int)VisWinTypes.visWinIDShapeSearch).Close();
Because I need to open multiple windows to display multiple visio files.So I opened up several windows simultaneously. In the first window, the Shape Search Window can be closed normally,but others can not. Please tell me how to solve this problem. Thanks!