var last;

function toggle(x){
  x = document.getElementById(x);
  if (x.style.visibility=='visible'){
    hide(x);
  } else {
    show(x)
  }
}

function show(x){
	x.style.visibility='visible';
	x.style.position='relative';
}
function hide(x){
	x.style.visibility='hidden';
	x.style.position='absolute';
}