// show or hide a DIV
function ShowBox(feed) 
{
	if (document.getElementById && document.getElementById(feed) != null) { document.getElementById(feed).style.visibility='visible'; document.getElementById(feed).style.display='block'; }
}

function HideBox(feed)
{
	if (document.getElementById && document.getElementById(feed) != null) { document.getElementById(feed).style.visibility='hidden'; document.getElementById(feed).style.display='none'; }
}

function ShowHide()
{
	var feed='back'; var StatusFeed = document.getElementById(feed).style.visibility; if (StatusFeed == null || StatusFeed=="" || StatusFeed=="visible") { HideBox(feed); } else { ShowBox(feed); }

}

// clear input value
function clearDefault(el) 
{
  if (el.defaultValue==el.value) el.value = ""
}