帮我指点下SQL SERVER数据库链接问题，谢谢！

C# code:
using System;
using System.Data;
using System.Configuration;
using System.Web;
using System.Web.Security;
using System.Web.UI;
using System.Web.UI.WebControls;
using System.Web.UI.WebControls.WebParts;
using System.Web.UI.HtmlControls;
using System.Data.SqlClient;
namespace Security
{

public class ValidateBase : System.Web.UI.Page
{
private string sqlConnStr;
private SqlConnection conn;
public ValidateBase()
{
this.sqlConnStr = "Data Source=192.168.1.102;Initial Catalog=didian_data;User=sa;Password=sa;";
}
public ValidateBase(string connStr)
{
this.sqlConnStr = connStr;
}
private void Open()
{
if (this.conn == null)
this.conn = new SqlConnection(this.sqlConnStr);
if (this.conn.State == ConnectionState.Closed)
this.conn.Open();
}
private void Close()
{
if (this.conn.State == ConnectionState.Open)
this.conn.Close();
if (this.conn != null)
this.conn.Dispose();
this.conn = null;
}
public void BuildParameters(SqlParameter[] param, ref SqlCommand comm)
{
//若参数不为空，则添加到命令对象
if (param != null