// Detect if the browser is IE or not.
// If it is not IE, we assume that the browser is NS.
var IE = document.all?true:false

// If NS -- that is, !IE -- then set up for mouse capture
if (!IE) document.captureEvents(Event.MOUSEMOVE)

// Set-up to use getMouseXY function onMouseMove
document.onmousemove = getMouseXY;

// variables to hold mouse x-y pos.s
var mouse_x = 0;
var mouse_y = 0;

// Main function to retrieve mouse x-y pos.s
function getMouseXY(e) {
    if (IE) {    
        mouse_x = event.clientX + document.body.scrollLeft;
        mouse_y = event.clientY + document.body.scrollTop;       
    } else {
        mouse_x = e.pageX;
        mouse_y = e.pageY;
    }
    if (mouse_x < 0) mouse_x = 0;
    if (mouse_y < 0) mouse_y = 0;    
    return true;
}