private void searchCompanyComboBox_SelectedIndexChanged(object sender, EventArgs e)
{
searchCategoryComboBox.Text = "";
searchCategoryComboBox.Items.Clear();
string selectedCompany = searchCompanyComboBox.Text;
StockInCategoryComboManager sInCatgComboMangObj = new StockInCategoryComboManager();
DataTable dt = sInCatgComboMangObj.GetCategoryNames(selectedCompany);
for (int i = 0; i < dt.Rows.Count; i++)
{
searchCategoryComboBox.Items.Add(dt.Rows[i]["Category"]);
}
}