//function to show/hide an element with a specified id
function switchElement(id){
  if (document.getElementById)
    if(document.getElementById(id).style.display != 'none')
      hideElement(id);
    else
      showElement(id);
}

//function to hide an element with a specified id
function hideElement(id) {

	if (document.getElementById) { 
		document.getElementById(id).style.display = 'none';
	}
}

//function to show an element with a specified id
function showElement(id) {		  
	if (document.getElementById) {
		document.getElementById(id).style.display = '';
	}

}