Uploading Pictures

[Biggie]

I have a question. If I upload tow different pictures, but they have the same file name, what will happen? will it replace the older file, or will it just change one of the filenames?

Is there a way that I can get around the problem (if there is one)?

[Nibbler]

The second file named filename.jpg would be renamed to filename~0.jpg, subsequent files being filename~1.jpg, filename~2.jpg and so on.