Access Session value in JavaScript function in ASP.Net

C#

protected void Page_Load(object sender, EventArgs e)
{
    string ab = (string)Session["UserID"]; // Read session
    Session["myValue"] = ab;
}

 script

<script type="text/javascript">
    var yourSessionValue = '<%= Session["myValue"] %>';
    alert(yourSessionValue);
</script>