Strange cookie bug, javascript

I cannot figure out why this is happening at all. I have a form, and a button that calls a method that uses jQuery to serializes the form and sticks it into a cookie, here:

function serializeFormToCookie(){
var str = $("form").serialize();
alert(str);

document.cookie = str + "&expires=" + expires.toUTCString()

alert("You have successfully stored your reservation, please click show if you would like to review it.")
}

(When I do a quick check and just alert(str) the string is exactly as I expect it.

There is a second button that calls a show method here is the show method:

function showData(){
var savedCookie = document.cookie
var dataArray = savedCookie.split("&")
alert(dataArray[0]) //this is blank! it should be the first key value pair from str!
alert(dataArray[1]) //this is "; key=value" I have NO idea where the ";" is coming from!
alert(datArray[2....etc]) //this is perfect, comes up as key=value.  
}

Can anyone figure out what is going on here?