I have a Login Problem in ASP.NET

using System;
using System.Data;
using System.Collections.Generic;
using System.Linq;
using System.Web;
using System.Web.UI;
using System.Web.UI.WebControls;
using System.Data.SqlClient;
using System.Configuration;

public partial class Login : System.Web.UI.Page
{
    protected void Page_Load(object sender, EventArgs e)
    {
        if (IsPostBack)
        {
            SqlConnection con = new SqlConnection(ConfigurationManager.ConnectionStrings["PassConnectionString"].ConnectionString);
            con.Open();
            string cmdStr = "select count(*) from TableCEO where EmailAddress='" + TextBox1.Text + "'";
            SqlCommand userExist = new SqlCommand(cmdStr, con);
            int temp = Convert.ToInt32(userExist.ExecuteScalar().ToString());
            con.Close();
            if (temp == 1)
            {
                Response.Write("User Name Already Exist!!!");
            }
        }
    }
    protected void Button1_Click(object sender, EventArgs e)
    {
        SqlConnection con = new SqlConnection(ConfigurationManager.ConnectionStrings["PassConnectionString"].ConnectionString);
        con.Open();

        string insCmd = "Insert into TableSecurity (EmailAddress, Password, Level) values (@EmailAddress, @Password, @Level)";
        SqlCommand insertUser = new SqlCommand(insCmd, con);
        insertUser.Parameters.AddWithValue("@EmailAddress", TextBox1.Text);
        insertUser.Parameters.AddWithValue("@Password", TextBox2.Text);
        insertUser.Parameters.AddWithValue("@Level", TextBox1.Text);





        string cmdStr = "select count(*) from TableCEO where EmailAddress='" + TextBox1.Text + "'";
            SqlCommand Checkuser = new SqlCommand(cmdStr, con);
            int temp = Convert.ToInt32(Checkuser.ExecuteScalar().ToString());
            if (temp == 1)
            {
                string cmdStr2 = "Select Password from TableSecurity where Password='" + TextBox2.Text + "'";
                SqlCommand pass = new SqlCommand(cmdStr2, con);
                string password = pass.ExecuteScalar().ToString();
                con.Close();

                if (password == TextBox2.Text)
                {
                    Session["New"] = TextBox1.Text;
                    Response.Redirect("Secure.aspx");
                }
                else
                {
                    Label1.Visible = true;
                    Label1.Text = "Invalid Password!!!";
                }
            }
            else
            {
                Label1.Visible = true;
                Label1.Text = "Invalid UserName!!!";

                
            }
        }
    }