function setPanel(panel, header, body) {
	// shows or hides the specified panel. body and header
	// booleans indicate which part of the panel 
	// needs to be shown or hidden
	if (header) {
		showBlock(panel + '_header');
		showBlock(panel + '_up');
		showBlock(panel + '_down');
	}
	else {
		hideBlock(panel + '_header');
	}
	if (body) {
		showBlock(panel + '_body');
		showBlock(panel + '_up');
		hideBlock(panel + '_down');
	}
	else {
		hideBlock(panel + '_body');
		showBlock(panel + '_down');
		hideBlock(panel + '_up');
	}
}

function showBlock(control) {
	// show specified block
	var control_handle = document.getElementById(control);
	control_handle.style.display = 'block';
}

function hideBlock (control) {
	// hide specified block
	var control_handle = document.getElementById(control);
	control_handle.style.display = 'none';
}