A simple Data Access Layer (DAL) in C#

using System;
using System.Data;
using System.Data.SqlClient;
using System.Configuration;
using System.Web;
using System.Web.Security;
using System.Web.UI;
using System.Web.UI.HtmlControls;
using System.Web.UI.WebControls;
using System.Web.UI.WebControls.WebParts;

///

/// Summary description for DAL
///

public abstract class DAL
{
static string strConnectionString = ConfigurationManager.ConnectionStrings["ConnectionString"].ConnectionString;
static SqlConnection connection = new SqlConnection(strConnectionString);
static SqlDataAdapter adapter;
static SqlCommand command;

public static SqlCommand DALCommand
{
get { return command; }
}

public static void InitDataAccess(string strStoredProcedure)
{
command = new SqlCommand(strStoredProcedure, connection);
command.CommandType = CommandType.StoredProcedure;
}

public static int ExecuteQuery()
{
return command.ExecuteNonQuery();
}

public static DataTable GetTable()
{
adapter = new SqlDataAdapter(command);
DataTable table = new DataTable();

adapter.Fill(table);

return table;
}

public static DataSet GetDataSet()
{
adapter = new SqlDataAdapter(command);
DataSet dataSet = new DataSet();

adapter.Fill(dataSet);

return dataSet;
}
}