Detecting similar opened window

[ken_shoti]

What code should i put to alert me if my page got another similar window opened. (I actually tried session cookies, but i want other options)!

[felgall]

When you open a window you can assign it to a variable:

myWin = window.open(...);

You can then test if myWin exists and if myWin.closed is false in order to determine that the window is still open (provided that you do it from the same page - once you leave the page then there is no link to the other window that can be tested from anywhere).

[ken_shoti]

No, i mean someone opened that same file again manually.