private void BindData()
{
using (var helper = new DbHelper.Subject())
{
var levelId = Convert.ToInt32(cmbLevel.SelectedValue == ""?"0":cmbLevel.SelectedValue);
var subjects = helper.ListSubjects(levelId);
grdView.DataSource = subjects;
grdView.DataBind();
//grdView.Columns.Add(new datacontrolfie); = "";
}
}