// JavaScript Document
function getItem(id){
	var itm = false;
	if(document.getElementById){
		itm = document.getElementById(id);
	}
	else if(document.all){
		itm = document.all[id];
	}
	else if(document.layers){
		itm = document.layers[id];
	}

	return itm;
}

function toggleMenu(block_id){
	//block_id is the id of the table block being hidden/shown.
	itm = getItem(block_id);

	if(!itm){
		return false;
	}

	if(itm.style.visibility == 'hidden'){
		itm.style.visibility = 'visible';
	}
	else{
		itm.style.visibility = 'hidden';
	}
}