ASP.NET后台显示信息、修改密码等操作

protected void Page_Load(object sender, EventArgs e)
{
//显示姓名等信息
string sql = "select * from [stu] where id="+Convert.ToString(Req【本文来自鸿网互联 (http://www.68idc.cn)】uest.QueryString["Id"]);
DataTable dt = new SqlHelper().ExecuteQuery(sql, CommandType.Text);
Label1.Text= Convert.ToString(dt.Rows[0]["stuname"]);

}
protected void Button1_Click(object sender, EventArgs e)
{
//修改密码等
string upsql = "update [stu] set [password]=" + TextBox1.Text.Trim() + "where id=" + Convert.ToString(Request.QueryString["Id"]);
int rows = new SqlHelper().ExecuteNonQuery(upsql, CommandType.Text);
Response.Write("