what do you mean by random?
Randomly from a list of servers or randomly from a list of subjects/keywords? At least you have to specify what image you are searching (image of what?) and where to get it (wich service/server). It's like you are asking to add two numbers but you're not giving the numbers.

btw, this thread may help you point toward one direction (at least)

Thanks for the reply ! I mean get as result a random (not specified by me in the sketch) image from Google Images! Is this even possible?   I know how to load and display images from the Internet but I have to specify the address (the link). Can the image be randomly selected ? Do I have to give a keyword or something?