IE7 has a 2 pixel border around the window which can not be styled/removed.
positioning elements within the body at 300px,200px will result in a mouse pointer location of 302px,202px. The following fix ensures that Opera, IE6/7, Firefox and Safari all return the same values. The work around I used was as follows
Prototype.Browser.IE7 = !!(window.attachEvent && !window.opera) && /MSIE 7/.test(navigator.userAgent);
if (Prototype.Browser.IE7) {
Event.pointer = function(event) {
return {
x: event.clientX + document.documentElement.scrollLeft - 2,
y: event.clientY + document.documentElement.scrollTop - 2
};
}
}