Check File on FTP Sever before Uploading

Question

How to check File Exist or Not On Ftp Server before Uploading

I have to upload file on Ftp Server every thing Working Fine but how can i just check the file exist on Ftp Server or not before uploading


I made my own control Using this example
http://www.c-sharpcorner.com/UploadFile/neo_matrix/SimpleFTP01172007082222AM/SimpleFTP.aspx