Problem with file upload

Ok, below is my codebehind for a photo gallery that deals with the upload control.  The problem I'm having is, if the file already exists, it tells me it already exists in the FileUploadReport, but the datagrid is still adding an entry to the database...and just uses the file that was already on the server instead of overwriting it.  What can I do to keep it from adding anything if the file already exists?

using System;
using System.IO;
using System.Collections;
using System.Configuration;
using System.Data;
using System.Linq;
u ...