function showElement(element) {
 if (document.getElementById(element)) {
 document.getElementById(element).style.display = 'block';
 }
}

function hideElement(element) {
 if (document.getElementById(element)) {
 document.getElementById(element).style.display = 'none';
 }
}

function toggleElementDisplay(element) {
 if (document.getElementById(element)) {
  if (document.getElementById(element).style.display == 'none') {
   document.getElementById(element).style.display = '';
  }
  else {
   document.getElementById(element).style.display = 'none';
  }
 }
}