Error in Validating the LoginPage

[rekhashanmugam]

namespace VendorProjNew
{
    public partial class frmLogIn : System.Web.UI.Page
    {
        
        protected void Page_Load(object sender, EventArgs e)
        {

        }

        string str = System.Configuration.ConfigurationManager.ConnectionStrings["VendorNewConnectionString"].ConnectionString;

        protected void btnSubmit_Click1(object sender, EventArgs e)
        {

            // to validate some field 

            if (this.Page.IsValid)
            {
                SqlConnection Objcon = new SqlConnection(str);
                // to store the data 
                DataTable dt = new DataTable();
                // opening the connection
                Objcon.Open();
                // passing the Sp name and the conn name
                SqlCommand oCmd = new SqlCommand("SP_Login_validate", Objcon);
                oCmd.CommandType = CommandType.StoredProcedure;
                oCmd.Parameters.AddWithValue("@vname", txtVendorName.Text);
                oCmd.Parameters.AddWithValue("@pwd", txtPasssword.Text);
                // to get details through database is accessed using data adapter
                SqlDataAdapter da = new SqlDataAdapter(oCmd);
                da.Fill(dt);
                oCmd.ExecuteNonQuery(); 
                Objcon.Close();
                Response.Redirect("VendorDetails.aspx");
            }

        }
       
    }
}

StoredProcedure :
create procedure SP_Login_valida te
@pwd nvarchar(20),
@vname nvarchar(50)
as
begin
SELECT [Password]
,[VendorName]
FROM [VendorNew].[dbo].[Login] where Password=@pwd and VendorName =@vname
end

[Rabbit]

You didn't say what the error is.