程序代码：

 protected void Button1_Click(object sender, EventArgs e)
    {
        string wd = TextBox1.Text.Trim();
        wd = HttpUtility.UrlEncode(wd, Encoding.Default);
        WebRequest wrq = WebRequest.Create("http://www.baidu.com/s?wd= " + wd + "&cl=3 ");
        WebResponse wrs = wrq.GetResponse();
        Stream strm = wrs.GetResponseStream();
        StreamReader sr = new StreamReader(strm, System.Text.Encoding.GetEncoding("gb2312"));

        string allstrm;
        allstrm = sr.ReadToEnd();

        Response.Write(allstrm);
        strm.Close();
    }

 string wd = TextBox1.Text.Trim();
        Response.Write("<script>window.open('http://www.baidu.com/s?wd= " + wd + "&cl=3')</script>");

string wd = TextBox1.Text.Trim();
        wd = HttpUtility.UrlEncode(wd, Encoding.Default);
        Response.Write("<script>window.open('http://www.baidu.com/s?wd= " + wd + "&cl=3')</script>");