/// <summary>
/// Try to find the text item and returns the index in the collection. If the
/// item is not found, the function returns -1.
/// </summary>
/// <param name="item">The text item to find.</param>
/// <returns>The ordinal number or double.NaN if the item is not found.</returns>
public int IndexOf(string item)
{
return(_itemList.IndexOf(item));
}
