Javascript onmousemove event not working

Question

Hi I have an image of a map and wish to find the coordinates. The code below is not working as it should...

The Javascript:

window.onload(init);

function init(){
var map = document.getElementById('map');
map.onmousemove = showCoords;
}

function showCoords(eventObj){
var coords = document.getElementById('coords');
var x = eventObj.clientX;
var y = eventObj.clientY;
coords.innerHTML = 'Map Coordinates: ' + x + ', ' + y;
}

The HTML:

<img id='map' src="images/map.jpg" alt="">
<p id='coords'>Move Mouse to get coords</p>

Answer 1

change

map.mousemove = showCoords;

to

map.mousemove = function(event) { showCoords(event) };