Simple login page button in asp.net

 protected void Button1_Click(object sender, EventArgs e)
    {
        Session["name"] = Convert.ToString(TextBox1.Text);
        SqlConnection con = new SqlConnection(ConfigurationManager.ConnectionStrings["con1"].ConnectionString);
        con.Open();
        SqlCommand cmd = new SqlCommand("loginselection", con);
        cmd.CommandType = CommandType.StoredProcedure;

        cmd.Parameters.AddWithValue("@username", TextBox1.Text);
        cmd.Parameters.AddWithValue("@password", TextBox2.Text);
        int a=Convert.ToInt32(cmd.ExecuteScalar());
        if (a > 0)
        {
            Label1.Text = "login sucessfully";
            Response.Redirect("~/Coursetopics.aspx");
            
        }
        else
        {
            Label1.Text = "check your username and password";
        }
            
       
    }

ALTER PROCEDURE [dbo].[loginselection](
@username varchar(20) ,
@password  varchar(20)

)
AS
BEGIN
-- SET NOCOUNT ON added to prevent extra result sets from
-- interfering with SELECT statements.
SET NOCOUNT ON;

    -- Insert statements for procedure here
SELECT * from UserDetails where UserName= @username and PsWrd =@password 
END