Tooltip concept in variable length Map

I have an image and i would like to change the image according to the user screen resolution. I intend to use tooltip and i wonder if i am able to use this without me specifying the coordinate of the place that i wanted to have tooltip ?? eg if i am using a 400*300 image, the tool tip will point exactly the same place as the one if i am using 800*600. coz if i use coordinate, it only applies to a size only and if the image is changed, the coordinate for the new image changed as well.

if it is possible to archieve this, how am i able to go about it ???

Also in #JavaScript _↴