/*
	toggles the display of certain table rows
	@(#) $Id$
	2008-06-01: Dr. Georg Fischer
*/
var disp = 'table-row';
function showHide() {
	if (disp == 'none') { 
		disp = 'table-row';
	} else {
		disp = 'none';
	}
	var elems = $$('tr.empty');
	var len = elems.length;
	for (var ind = 0; ind < len; ind ++) {
		elems[ind].style.display = disp;
	}
}