$('img').click(function(e) {
var position = 'X: ' + (e.layerX || e.offsetX) + ' Y: ' + (e.layerY || e.offsetY);
alert('Click position within image: ' + position);
});
JavaScript Get mouse click position within an element
Older browsers such as IE 7 & 8 use different event properties to reveal the mouse click coordinates within an element.