I am experimenting with the computed field.
In D7, I created a node type with 3 fields...

field_android_appiconpng is an image
field_android_res_long_land_ldpi is a second image

the third field is a computed field...
the code for Display Code (PHP) is:

$display_output = '<button class="ui-button ui-widget ui-state-default ui-corner-all ui-button-text-only" role="button" aria-disabled="false"><span class="ui-button-text">' . t('Download as zip') .'</span></button>';

My goal is to create a button that will take both image files and zip them into a file that will extract to:
/dir01/imagefile.png
/dir02/imagefile.png

so the images are saving to different dirs.
Can I get some assistance on how this is done.. so when the button is clicked it will download the single ZIP file?
thanks