How to delete the file uploaded using feeds importer before another file is uploaded using the same importer

Hi ,

I am using Feeds importer to upload the phonebook. Everything is fine. But I notice one issue.

MY phone book contains 2000 records and converting to CSV and uploading the file where I notice is that each record is created a node so there are 2000 nodes, what if next time when we update phonebook again will there be another 2000 nodes generated.

Do I have to delete all the nodes from last upload?

We have this phonebook update every month (Update may be new employees joined or change in phone, locations for existing employees)

on the Node Processor Settings I have selected:

Update existing nodes
Do not update existing nodes

Am I doing something wrong? Please do the needful.

Thanks in advance.

Rev