function hideDiv(whichLayer){
	if (document.getElementById){
	// this is the way the standards work
		var divStyle = document.getElementById(whichLayer).style;
		divStyle.visibility = 'hidden';
	}
	else if (document.all){
	// this is the way old msie versions work
	var divStyle = document.all[whichLayer].style;
	divStyle.visibility = 'hidden';
	}
	else if (document.layers){
	// this is the way nn4 works
	var divStyle = document.layers[whichLayer].style;
	divStyle.visibility = 'hidden';
	}
}