if i have file name "file" on my ftp server in some folder and i want to upload a new file with same name "file" at the same folder. so it will create problom or it will modifiy the existing file.

i have the following error message

1 Warning: ftp_fput() [function.ftp-fput]: Access is denied. in G:\WEBROOT\aa\ftpcopy_ver2.php on line 34
There was a problem while uploading SD66.zip
2 Warning: ftp_site() [function.ftp-site]: SD66.zip: No such file or directory. in G:\WEBROOT\aa\ftpcopy_ver2.php on line 45

FTP_PUT () overrites files without warning. I have no idea about ftp_fput(), but I suppose it will overwrite as well, that is - it will replace content.

Why don't you try with a simple txt file on your own.