I have a multiple language site. With html, javascript, may be ajax if an image does not exist in spanish folder, it should load image from the english folder.
path example
english site : images/home.jpg
spanish site : es/images/home.jpg
Today i have message.properties … stuff for doing text conversion
message.properties
message_es.properties
You can use onerror for the image
but, IMHO, it is better to do the job on server side