Custom Membership, Role Providers, Website administration tool, and Role based access to individual files

using System;
using System.Data;
using System.Configuration;
using System.Collections;
using System.Web;
using System.Web.Security;
using System.Web.UI;
using System.Web.UI.WebControls;
using System.Web.UI.WebControls.WebParts;
using System.Web.UI.HtmlControls;

public partial class Admin_Users_Default : System.Web.UI.Page
{
    static int _currentRecord;

    protected void Page_Load(object sender, EventArgs e)
    {

        if (!Page.IsPostBack)
        {
            _currentRecord = 1;
        }
        else
        {
        }

    }
    protected void Page_PreRender(object sender, EventArgs e)
    {
        MembershipUserCollection allUsersCollection = Membership.GetAllUsers();
        ArrayList allUsers = new ArrayList();

        foreach(MembershipUser usr in allUsersCollection)
        {
            allUsers.Add(usr.UserName.ToString());
        }
        lblTotal.Text = allUsers.Count.ToString();

        username.Text = allUsers[_currentRecord - 1].ToString();
        
        String[] allRoles = Roles.GetAllRoles();
        
        userList.DataSource = allUsers;
        userList.DataBind();
        UserRoles.DataSource = allRoles;
        UserRoles.DataBind();

        userList.SelectedIndex = _currentRecord - 1;

        navlinksettings();
        roleboxsettings();
        lblCurrent.Text = _currentRecord.ToString();

    }

    protected void NavigationLink_Click(object sender, CommandEventArgs e)
    {
        switch (e.CommandName)
        {
            case "First":
                _currentRecord = 1;// _currentPageNumber = 1;
                break;
            case "Last":
                _currentRecord = Int32.Parse(lblTotal.Text);//_currentPageNumber = Int32.Parse(TotalPages.Text);
                break;
            case "Next":
                _currentRecord = Int32.Parse(lblCurrent.Text) + 1;//_currentPageNumber = Int32.Parse(CurrentPage.Text) + 1;
                break;
            case "Prev":
                _currentRecord = Int32.Parse(lblCurrent.Text) - 1;// _currentPageNumber = Int32.Parse(CurrentPage.Text) - 1;
                break;
        }
    }
    protected void btnExit_Click(object sender, EventArgs e)
    {
        FormsAuthentication.SignOut();
        Response.Redirect("~/Login.aspx");
    }
    protected void btnNew_Click(object sender, EventArgs e)
    {
        Response.Redirect("Create_User.aspx");
    }

    private void navlinksettings()
    {
        if (_currentRecord == 1)
        { btnPrevious.Enabled = false; }
        else
        { btnPrevious.Enabled = true; }
        if (_currentRecord == Int32.Parse(lblTotal.Text))
        { btnNext.Enabled = false; }
        else
        { btnNext.Enabled = true; }
    }

    protected void btnSave_Click(object sender, EventArgs e)
    {
        UpdateUserRoles();
    }
    protected void btnCancel_Click(object sender, EventArgs e)
    {

    }
    protected void btnEdit_Click(object sender, EventArgs e)
    {
        Membership.DeleteUser(username.Text.ToString(), true); // DC: except during testing, of course!
        _currentRecord -= 1;
        Response.Redirect("Default.aspx");
    }

    private void UpdateUserRoles()
    {
        foreach (ListItem rolebox in UserRoles.Items)
        {
            if (rolebox.Selected)
            {
                if (!Roles.IsUserInRole(username.Text, rolebox.Text))
                {
                    Roles.AddUserToRole(username.Text, rolebox.Text);
                }
            }
            else
            {
                if (Roles.IsUserInRole(username.Text, rolebox.Text))
                {
                    Roles.RemoveUserFromRole(username.Text, rolebox.Text);
                }
            }
        }
    }

    private void roleboxsettings()
    {
        foreach (ListItem rolebox in UserRoles.Items)
        {
           if (Roles.IsUserInRole(username.Text, rolebox.Text))
                {
                    rolebox.Selected = true; 
                }
            else
            {
                rolebox.Selected = false;
            }
        }
    }
    protected void userList_SelectedIndexChanged(object sender, EventArgs e)
    {
        userList.DataBind();
        _currentRecord = userList.SelectedIndex + 1;
    }
}