If you are wanting to check you data before uploading and have access to MS Excel, there is a Remove Duplicates function in the Data tab of the ribbon. You can select the columns in question one at a time and the Remove Duplicates function will delete duplicates and tell you the number of records that were duplicate. You could also insert a PivotTable and create a count of your records to see if there are more than one records with the same value. A third option is conditional formatting; there is an option to highlight cells that have duplicates.
------------------------------
Adam Keever
------------------------------