protected void Note_Info()
{
string stuId = Session["userId"].ToString();
string sql = "select * from NoteInfo inner join VideoInfo on NoteInfo.videoId = VideoInfo.videoId inner join CourseInfo on CourseInfo.courseId = VideoInfo.CourseId where stuId='" + stuId + "'";
NoteInfo.DataSource = DataOperate.GetDataset(sql, "NoteInfo");
NoteInfo.DataKeyField = "NoteId";
NoteInfo.DataBind();
}