image pop-up on rollover

[mikes02]

im fairly new here so if this is in the wrong forum i apologize.

i am working on a map and i want to have a magnifying glass icon next to a specific location where on rollover it displays a larger image showing that location in detail, what is the easiest and most efficient way of accomplishing this effect?

thanks!

[mikes02]

maybe i am not describing this accurately, i don't mean a pop up like a pop up window, i just want the image to show up on the screen on rollover.