主题：[求助]关闭并列窗口问题

单击并列窗口标题栏的【X】，如何实现:先出现对话框提示是否关闭

谢

新问题：一并列窗口中加入了另一独立窗口，

Forms("并列窗口1").Open
Forms("并列窗口1").Text = "导航菜单设计"
Dim PB As WinForm.Panel = Forms("并列窗口1").Controls("Panel1")
Dim Name As String = "导航菜单设计"
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.BaseControl.Controls.Clear
PB.BaseControl.Controls.add(Forms(Name).BaseForm)

单击【X】关闭后再打开，提示：并列窗口1已关闭

问题2：打开并列窗口要单击两次，是怎么回事