hidd = 0; id = 0;
function f_visib(element) {
  i = 1; hidd = 1;
  while (e = document.getElementById("f" + i++)) 
    e.style.visibility = "hidden";
  document.getElementById(element).style.visibility = "visible";
}

function end_vis() {
  clearTimeout(id);
  hidd=0; id = setTimeout(hid_vis, 200)
}

function hid_vis() {
  if (hidd==0) {
    i = 1; 
    while (e = document.getElementById("f" + i++)) 
      e.style.visibility = "hidden";
  }
}

function form(obj) {
	var el = document.getElementById(obj);
	el.style.display = (el.style.display != 'none' ? 'none' : '' );
}