private void BindSizeOrModel()
{
int id = 0;
Int32.TryParse(ddlMainCategory.SelectedValue, out id);
UnitTypeDAL dal = new UnitTypeDAL();
List <UnitTypeModel> lst = dal.BindDataByMainCat(id);
ddlSizeOrModel.DataSource = lst;
ddlSizeOrModel.DataTextField = "Name";
ddlSizeOrModel.DataValueField = "ID";
ddlSizeOrModel.DataBind();
ddlSizeOrModel.Items.Insert(0, new ListItem("Select One", ""));
}