protected void DropDownList1_SelectedIndexChanged(object sender, EventArgs e)
{
string result = DropDownList1.SelectedValue.ToString();
if (result == "1")
{
GridView1.DataSource = bm.BindGradeListBySum(Request.QueryString["courseid"].ToString());
GridView1.DataBind();
}
else if (result == "2")
{
GridView1.DataSource = bm.BindGradeListByAvg(Request.QueryString["courseid"].ToString());
GridView1.DataBind();
}
else
{
GridView1.DataSource = bm.BindGradeListByNumber(Request.QueryString["courseid"].ToString());
GridView1.DataBind();
}
}