Page reload causing socket.io disconnection

I try to develop a tchat with socket.io, when a new user is connected I add it to my array users and when disconnected I remove it from array users

When the client reloads page, it considers as a disconnection, and it gets removed,

How to avoid removing when reloading the page.

 socket.on('disconnect', function(data){
        /*isConnected = false;
        setTimeout(function(){
            if ( !isConnected )
            {*/
                if (!socket.username) return;
                delete oUsers[socket.username];
                if ( socket.sexe == "femme" ) socket.broadcast.to('boys').emit('user offline', socket.username);
                else socket.broadcast.to('girls').emit('user offline', socket.username);
        /*  }
        }, 5000);*/
    });