function toggleElements() {
 
	// toggles the visibility of elements
	// sample usage : onclick="toggleElements('show', 'element_1', 'element_2'); etc...
	// the 1st argument is the visibility mode (show or hide)
	// other arguments are the IDs of the elements to manipulate
 
	if (!arguments) return false;
	if (arguments[0] != 'show' && arguments[0] != 'hide') return false;
 
	var v_mode = arguments[0];
 
	for (i = 0; i < arguments.length; i++) {
 
		var element_id = arguments[i];
 
		if (!document.getElementById(element_id)) continue; // no element with this ID exists
 
		if (v_mode == 'show') {
			document.getElementById(element_id).style.display = '';
		} else {	
			document.getElementById(element_id).style.display = 'none';
		}
	}	
}