主题：窗口代码错误

无语

Dim tab As winform.tabcontrol=e.Form.controls("tabcontrol3")
If tab.tabpages("窗口1") IsNot Nothing Then
tab.Selectedpage = tab.tabpages("窗口1")
Else
Dim name As String = "窗口1"
tab.tabpages.Add(name,name)
Dim pb =tab.basecontrol
Forms(name).open(-1000,-1500)
Forms(name).baseform.Toplevel = False
Forms(name).baseform.Formborderstyle = system.windows.Forms.Formborderstyle.none
Forms(name).baseform.Dock = system.windows.Forms.dockstyle.fill
pb.tabpages(name).controls.clear
pb.tabpages(name).controls(Forms(name).baseform)
tab.Selectedpage = tab.tabpages(name)
End If