Trouble with "Last Login" Stored Procedure - asp.net

Question

Added a column "LastLogin" to a User table, however, it only stores the last login date the first time a user logs in to a password-protected page.
When the same user logs in a second time, the cell does not reflect his last login. Here is my stored procedure:
Here is my stored procedure:
ALTER PROCEDURE [dbo].[UpdateLastLogin] (
#intUserID int
)
-- Add the parameters for the stored procedure here
AS
SET NOCOUNT ON
UPDATE Users SET LastLogin = GETDATE() WHERE UserID = #intUserID
Here is my code:
public partial class Login : System.Web.UI.Page
{
protected void Page_Load(object sender, EventArgs e)
{
//SqlConnection oConnection = new SqlConnection(ConfigurationManager.ConnectionStrings["XXXConnectionString"].ConnectionString);
//SqlCommand oCommand = new SqlCommand();
//oCommand.Connection = oConnection;
//oCommand.CommandText = "UpdateLastLogin";
//oCommand.CommandType = CommandType.StoredProcedure;
//oCommand.Parameters.Add(new SqlParameter("#intUserID", SqlDbType.NVarChar, 10)).Value = Int32.MaxValue;
//SqlDataAdapter adpt = new SqlDataAdapter(oCommand);
//DataSet ds = new DataSet();
//adpt.Fill(ds);
}
protected void loginButton_Click(object sender, EventArgs e)
{
SqlConnection con = new SqlConnection(ConfigurationManager.ConnectionStrings["3GPSConnectionString"].ConnectionString);
con.Open();
string cmdStr = "Select count(*) from Users where UserName='" + userTextBox.Text + "'";
SqlCommand Checkuser = new SqlCommand(cmdStr, con);
int temp = Convert.ToInt32(Checkuser.ExecuteScalar().ToString());
if (temp == 1)
{
string cmdStr2 = "Select Password from Users where UserName='" + userTextBox.Text + "'";
SqlCommand pass = new SqlCommand(cmdStr2, con);
string password = pass.ExecuteScalar().ToString();
con.Close();
if (password == pwdTextBox.Text)
{
Session["New"] = userTextBox.Text;
Response.Redirect("/Protected/Default.aspx");
}
else
{
userCompareLbl.Visible = true;
userCompareLbl.Text = "Invalid Password!";
}
}
else
{
userCompareLbl.Visible = true;
userCompareLbl.Text = "Invalid Username!";
}
}
}