/// <summary>
        /// Handles clicks of the "add keyword" context menu item.
        /// </summary>

        private void addKeywordMenuItem_Click(object sender, EventArgs e)
        {
            if (this.selectedLoc != null)
            {
                using (var addKeywordForm = new AddKeywordForm(this.keywordList))
                {
                    if (addKeywordForm.ShowDialog() == DialogResult.OK)
                    {
                        AddKeywordsToLocation(this.selectedLoc, addKeywordForm.SelectedKeywords);
                    }
                }
            }
        }
        /// <summary>
        /// Handles clicks of the "add keywords" context menu item on the context
        /// menu for the flat location list.
        /// </summary>

        private void addKeywordsToFlatListLoc_Click(object sender, EventArgs e)
        {
            if (this.locListBox.SelectedItems.Count > 0)
            {
                using (var addKeywordForm = new AddKeywordForm(this.keywordList))
                {
                    if (addKeywordForm.ShowDialog() == DialogResult.OK)
                    {
                        foreach (string selectedLoc in this.locListBox.SelectedItems)
                        {
                            AddKeywordsToLocation(selectedLoc, addKeywordForm.SelectedKeywords);
                        }
                    }
                }
            }
        }