swap image name ?

[eluser]Zeeshan Rasool[/eluser]
Is there any body who can help me??

I need to swap two files for example

/photos/jim1.jpg

and

/photos/jim3.jpg

if I need jim3 to become jim1 and jim1 to become jim3 do I need to first save one of them as a new file or is there some kind of swap command that will just swap the two?
anyway help is appreciated I am currently working on it to rename jim1 to swap and rename jim3 to jim1 and then swap to jim3. is there an easier way?