protected void companyDropDownList_SelectedIndexChanged(object sender, EventArgs e)
{
int companyId = Convert.ToInt32(companyDropDownList.SelectedValue);
itemDropDownList.DataTextField = "ItemName";
itemDropDownList.DataValueField = "ItemID";
itemDropDownList.DataSource = stockInManager.GetAllItems(companyId);
itemDropDownList.DataBind();
itemDropDownList.Items.Insert(0, new ListItem("<Select Subject>", "0"));
}