//store the key in a cookie
SetCookie('rediskey', <%= rediskey %>); //http://msdn.microsoft.com/en-us/library/ms533693(v=vs.85).aspx
//then when socket is connected, fetch the rediskey from the document.cookie and send it back to server
var socket = new io.Socket();
socket.on('connect', function() {
var rediskey = GetCookie('rediskey'); //http://msdn.microsoft.com/en-us/library/ms533693(v=vs.85).aspx
socket.send({rediskey: rediskey});
});