//dropdownlist学院列绑定
private void drpBind()
{
TermsManage tm = new TermsManage();
CollegesManage cm = new CollegesManage();
DropDownList1.DataSource = tm.Select();
DropDownList1.DataTextField = "term";
DropDownList1.DataBind();
DropDownList2.DataSource = cm.Select();
DropDownList2.DataTextField = "college";
DropDownList2.DataBind();
ddl3bind();
}