Upload/Crop Image - 2 minutes work - maxTotalCost 10$

Two minutes job for anyone knows about it! - PHP

I have this script http://www.defusion.org.uk/demos/060519/cropper.php
When the user select an area, crop values(x1,y1,x2,y2,width,height) appear.

I want let a user upload an image (.gif/.jpg/.png) in a temporary folder (/tmp)
Then let the user select the area he prefer (with the script above)
After the submit, a php file get the values ($x1 = $_POST['x1']',....)
Crop the image with the above values
Upload the new image (new_image.jpg) in a new folder (/images) with extension .jpg
Finally, delete the old image in the tmp folder.

Attention: I want upload .gif & .png & .jpg & .JPG files. The export must be .jpg / QUALITY 100
Photos are uploaded ussuelly from Olympus or Sony Camera

Please write the code with //comments to underastand anythingyou write