capturing f5 keypress event in javascript using window.event.keyCode in [removed] event is always 0 and not 116

Question

i am creating an MVC application.There was a neccessitity to make a variable in a session to null upon closing of the application (i.e. window/tab) but not upon refreshing t

Answer 1

Modified version and working also after pressing 't'.

key 116 getting pressed auto after 84

document.onkeydown = fkey;
document.onkeypress = fkey
document.onkeyup = fkey;

var wasPressed = false;

function fkey(e){
    e = e || window.event;
   if( wasPressed ) return; 

    if (e.keyCode == 116) {
         alert("f5 pressed");

    }else {
        alert("Window closed");
    }
    wasPressed = true;
}