It takes the user’s computer time not the server time.

function getMouseXY(e) // works on IE6,FF,Moz,Opera7
{
if (!e) e = window.event; // works on IE, but not NS (we rely on NS passing us the event)

if (e)
{
if (e.pageX || e.pageY)
{ // this doesn’t work on IE6!! (works on FF,Moz,Opera7)
tempX = e.pageX;
tempY = e.pageY;
algor = ‘[e.pageX]‘;
if (e.clientX || e.clientY) algor += ‘ [e.clientX] ‘
}
else if (e.clientX || e.clientY)
{ // works on IE6,FF,Moz,Opera7
// Note: I am adding together both the “body” and “documentElement” scroll positions
// this lets me cover for the quirks that happen based on the “doctype” of the html page.
// (example: IE6 in compatibility mode or strict)
// Based on the different ways that IE,FF,Moz,Opera use these ScrollValues for body and documentElement
// it looks like they will fill EITHER ONE SCROLL VALUE OR THE OTHER, NOT BOTH
// (from info at http://www.quirksmode.org/js/doctypes.html)
tempX = e.clientX + document.body.scrollLeft + document.documentElement.scrollLeft;
tempY = e.clientY + document.body.scrollTop + document.documentElement.scrollTop;
algor = ‘[e.clientX]‘;
if (e.pageX || e.pageY) algor += ‘ [e.pageX] ‘
}
}
}

Nice tool by the way ..