how to Avoid open the same window twice in a new tab in c#

Question

How to avoid to open same window of existing website(window) in new tab

for eg.. if i have a page www.mysite.com/page1.aspx if i copy this URL and paste in new tab of the browser than a popup or message should be appear(alert-- you have already open this website)

Note: if we reload or refresh the previous page than alter should not be appear .means only one page can be open at a time

It should be done in scripting only, i need your valuable advice thanks in advance

Answer 1

Create a cookie, set its value to true on page load and false on log off. check if a cookie is true and same page loaded show your message.