Javascript cannot retrieve cookies between Windows OS pages

I am using TideSDK to develop a desktop app for windows. I am trying to use a cookie to store the information of the email address that a user enters on login. The cookie that I save for the email address (on my index.html file) somehow becomes lost when the next page (mainMenu.html) loads.

index.html Javascript:

//this is what I call when the login information is correct



function setCookie(cname,cvalue,exdays) {

             var d = new Date();
             d.setTime(d.getTime() + (exdays*24*60*60*1000));
             var expires = "expires=" + d.toGMTString();
             document.cookie = cname+"="+cvalue+"; "+expires;

             }

        function getCookie(cname) {
        var name = cname + "=";
        var ca = document.cookie.split(';');
        for(var i=0; i<ca.length; i++) {
        var c = ca[i];
        while (c.charAt(0)==' ') c = c.substring(1);
        if (c.indexOf(name) != -1) return c.substring(name.length, c.length);
        }
        return "";
        }


        setCookie("email",em,30); //setting the cookie

        window.location.href = "mainMenu.html"; // go to the next page 

mainMenu.html Javascript:

//this is what I call when the page gets loaded

function getCookie(cname) {
    var name = cname + "=";
    var ca = document.cookie.split(';');
    for(var i=0; i<ca.length; i++) {
        var c = ca[i];
        while (c.charAt(0)==' ') c = c.substring(1);
        if (c.indexOf(name) != -1) return c.substring(name.length, c.length);
    }
    return "";
}
   alert("email: "+getCookie("email"));

This is what the alert statment from my mainMenu.html looks like:

Why is my cookie not saved between files?

Thank you in advance!!!! Please let me know if I was too vague or left anything out, I will gladly explain myself!!! :)

Since tidesdk is not properly a "browser" cookies may not work as expected. use a JSON structure to save such information. Please read the topic about your cookies here

TideSDK How to save a cookie's information to be accessed in different file?

Cookies may not be the best option for tidesdk to store information.