function hide_reveal(element_id)
{
	var opening_text = "Lue lisää...";
	var closing_text = "Pienennä takaisin...";
	
	var element = document.getElementById(element_id + "_text");
	var link = document.getElementById(element_id + "_link");
	if(element.style.display == "block")
	{
		element.style.display = "none";
		link.innerHTML = opening_text;
  	}
	else
	{
		element.style.display = "block";
		link.innerHTML = closing_text;
	}
}