help!!!! urgent...

for my final project i need to swap 2 image and send it to another form..

for clear, my project is to make a bus company website..then my lecturer want the bus seat in graphical appearance...so i think the best way is make an image swap, if other seat was differ from it...and when submit, it will send an image name, to validation before make it to the database..
coz i'm amateur so brain cannot think of it...huhuhu
i have less than 1 week to make it....please...