Where everybody clicked

This is done by putting the map (or comet) in a div, and all the red circles in child div's with position:absolute and with style specifying left & top (measured from the containing comet image).
z-index doesn't seem to be necessary. div "comet " must be relative, I offset the image relatively with a style, (to center the circles, otherwise the left top would be at the click)

This example shows 4 red circles. I made the circles with KIconEdit. For a script I would query for all the coordinates, and write the repeating div's, giving the x,y coordinates.