How to get a username from Membership Structure of Asp.net

Dear all,
           I am using the asp.net built-in Membership structure. How can I get the username that is
just logging?  I have the following code:
public partial class login : System.Web.UI.Page
{
    protected void Page_Load(object sender, EventArgs e)
    {
        FormsAuthentication.SignOut();
        Master.disableMenu();
    }
   
protected void loginControl_LoggedIn(object sender, EventArgs e)
    {
        if (!Roles.IsUserInRole("subscribers") && !Roles.IsUserInRole("staff"))
        {
            loginControl.FailureText = " ...