how to make session in javascript code example

Example 1: javascript create cookie

function setCookie(name,value,days) {
    var expires = "";
    if (days) {
        var date = new Date();
        date.setTime(date.getTime() + (days*24*60*60*1000));
        expires = "; expires=" + date.toUTCString();
    }
    document.cookie = name + "=" + (value || "")  + expires + "; path=/";
}
function getCookie(name) {
    var nameEQ = name + "=";
    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,c.length);
        if (c.indexOf(nameEQ) == 0) return c.substring(nameEQ.length,c.length);
    }
    return null;
}

setCookie("user_email","[email protected]",30); //set "user_email" cookie, expires in 30 days
var userEmail=getCookie("user_email");//"[email protected]"

Example 2: how to use session using javascript

BY LOVE
sessionStorage.setItem("SessionName", "SessionValue");

Example 3: set a value in session using javascript

<script type="text/javascript">
    function GetUserName()
    {

        var username = '<%= Session["UserName"] %>';
        alert(username );
    }
</script>