var rightArrow = new Image();
var downArrow = new Image();
rightArrow.src = "images/rarr.png";
downArrow.src = "images/darr.png";

function toggleElementVisibility( target )
{
	var element = document.getElementById( target );
	var element_image = document.getElementById( target + "_arrow" );
	
	if ( !element || !element_image )
	{
		return true;
	}
	
	if ( element.style.display == "none" || element.style.display == "" )
	{
		element.style.display = "block";
		element_image.src = downArrow.src;
	}
	else
	{
		element.style.display = "none";
		element_image.src = rightArrow.src;
	}
	return true;
}