function checkAll(aBox) {
	if (aBox.checked) {
		window.primarysearch.category_all.checked = false;
	}
}

function clearAll(aBox) {
	if (aBox.checked) {
		field = window.primarysearch;
		for (i = 0; i < field.length; i++) {
				field[i].checked = false ;
		}
		aBox.checked = true;
	}
}