how to know user have open browser ?

hi guys,
how to know user have open browser ? which one method can listening when user open browser ?

 

I'm having a hard time trying to figure out what exactly your question is. Can you be more specific, or give an example so I can understand your question better.

 

if they click a link to launch a new window, you can name that window and check if it is open using javascript:

win = window.open();
if(win){
//the window is open!
}

 

Thanks canadianguy_001 but i didnt understood that!