Column's Value Is Likely To Be Unique 90% Of Time

For each loop through a DataSet, I need to store the values of 2 columns (we'll call them ColumnA and ColumnB) so that I can use them to search the same DataSet again later.The DataSet stores the results of a search and places the value of ColumnA into a ListBox as a new item.When the user clicks on this ListBox item, the application will loop through the DataSet again using the value of ColumnA and the value of ColumnB as criteria to identify the correct row in the DataSet to return.This would be a lot simpler if the value for ColumnA was unique every time, but a value will inevitably be repeated on occasion. That's where ColumnB comes in. This column's value is likely to be unique 90% of the time, and, given the nature of the information in the DataSet, if either column duplicates, the other won't.So I've thought of adding the values for ColumnA and ColumnB into a 2 dimensional dynamic array, but I'm doing something wrong apparently.[code]