哪位大神能帮我把MD5加密的登陆模式换成普通的登陆模式

这个是我完整的代码，管理的那里我不知道设计，我在数据库设计的密码为123456，不过我知道加密后就不是123456,；可我不知道怎么设计加密密码，
public partial class login_usercontrol : System.Web.UI.UserControl
{
    String SqlStr;
    DB db = new DB();
    DataSet Ds = new DataSet();
    protected void Page_Load(object sender, EventArgs e)
    {

    }
    protected void btn_Login_Click(object sender, EventArgs e)
    {
        String Md5_User_Pwd = FormsAuthentication.HashPasswordForStoringInConfigFile(this.txt_User_Pwd.Text.ToString(), "MD5");
        SqlStr = "select * from 会员表 where 会员名='" + this.txt_User_Name.Text + "' and 密码='" + Md5_User_Pwd + "'";
        Ds = db.GetDataTableBySql(SqlStr);
        try
        {
            if (Ds.Tables[0].Rows.Count == 0)
            {
                this.Labinfo.Text = "用户名或密码错误，请重试！";
                this.txt_User_Name.Focus();
            }
            else
            {
                this.Labinfo.Text = "用户  " + this.txt_User_Name.Text + "  恭喜您登录成功！";
                Session["UserName"] = this.txt_User_Name.Text;
            }
        }
        catch (Exception)
        {
            this.Labinfo.Text = "没有得到任何数据，请重试！";
        }
    }
    protected void btn_Register_Click(object sender, EventArgs e)
    {
        Response.Redirect("zhuce.aspx");
    }


    protected void Button1_Click(object sender, EventArgs e)
    {
     String Md5_User_Pwd = FormsAuthentication.HashPasswordForStoringInConfigFile(this.txt_User_Pwd.Text.ToString(), "MD5");  
        SqlStr = "select * from 管理员表 where 用户名='" + this.txt_User_Name.Text + "' and 密码='" + Md5_User_Pwd + "'";
        Ds = db.GetDataTableBySql(SqlStr);
        try
        {
            if (Ds.Tables[0].Rows.Count == 0)
            {
                this.Labinfo.Text = "用户名或密码错误，请重试！";
                this.txt_User_Name.Focus();
            }
            else
            {
               this.Labinfo.Text = "管理员  " + this.txt_User_Name.Text + "  恭喜您登录成功！";
               Session["Admin_UserName"] = this.txt_User_Name.Text;
            }
        }
        catch (Exception)
        {
            this.Labinfo.Text = "没有得到任何数据，请重试！";
        }
    }
}