"Object doesn't support this property or method"

[admin]

got my clock working on the website using a javascript function held on a file. this file also hold all my pop out menu javascript.

Now the clock is working when i mouse over a region in the pop out menu i get the error - "Object doesn't support this property or method"

the line it points to is

if (document.layers) {
if (a) {
a.document.bgColor = a.saveColor;
if (a.hilite) a.hilite.visibility = "hidden";
if (a.Menu.bgImageOver) a.background.src = a.Menu.bgImageUp;
a.focusItem.top = -100;
a.clicked = false;
}

any ideas
thanks