How to prevent multiple identical windows from being opened at the same time?

1. if it is in the web, it is too simple. When you open the Page Link, specify target = new (target = ABC, target = ABCD ...).
If it is in winform, it will be a little troublesome, and Zhijin has not found a very good method.

2. use the mode window (JavaScript), that is, window. showmodaldialog (". aspx "," "," dialogwidth = 100px; dialogheight = 100px; help = no; status = no; scroll = No ")

Why does the ASPX page reopen a page when showmodeldialog is submitted?
On the showmodaldialog page, add a line between

3.

<Script language = "JavaScript">
<! --
Window. Open ("AAA. asp", "new", "width = 700, Height = 500, toolbar = No, status = yes ")

// -->
</SCRIPT>