How to get return value from SQl query thru Dot Net

first create the "dyntable " procedure 

CREATE  PROCEDURE dyntable (@new_var int  Output )

AS

BEGIN

   Select @new_var=count(*) from admin_master

   return @new_var

END

GO

Get return value in Asp.Net 

        string intconfirm = "";

      

        SqlConnection conn = new SqlConnection(objconn.GetConnection());

        SqlCommand cmdInsert = new SqlCommand("dyntable", conn);

        cmdInsert.CommandType = CommandType.StoredProcedure;

        SqlParameter var =new SqlParameter("@new_var",SqlDbType.Int); 

        var.Direction = ParameterDirection.Output;

        cmdInsert.Parameters.Add(var);

        conn.Open();

        SqlDataReader dtread;

        cmdInsert.ExecuteNonQuery();

        string str = Convert.ToString(cmdInsert.Parameters["@new_var"].Value);       

        conn.Close();