function element_toggle(element_id)
{
  try {
    if (document.layers) {
      current = (document.layers[element_id].display == 'none') ? 'block' : 'none';
      document.layers[element_id].display = current;
    }
    else if (document.all) {
      current = (document.all[element_id].style.display == 'none') ? 'block' : 'none';
      document.all[element_id].style.display = current;
    }
    else if (document.getElementById) {
      vista = (document.getElementById(element_id).style.display == 'none') ? 'block' : 'none';
      document.getElementById(element_id).style.display = vista;
    }
  } catch(e) {}
}

function element_invisible(element_id) {
  try {
    if (document.layers)
      document.layers[element_id].display = 'none';
    else if (document.all)
      document.all[element_id].style.display = 'none';
    else if (document.getElementById)
      document.getElementById(element_id).style.display = 'none';
  } catch(e) {}
}

function element_visible(element_id) {
  try {
    if (document.layers)
      document.layers[element_id].display = 'block';
    else if (document.all)
      document.all[element_id].style.display = 'block';
    else if (document.getElementById)
      document.getElementById(element_id).style.display = 'block';
  } catch(e) {}
}



function element_hide(element_id) {
  try {
    if (document.layers)
      document.layers[element_id].display = 'none';
    else if (document.all)
      document.all[element_id].style.display = 'none';
    else if (document.getElementById)
      document.getElementById(element_id).style.display = 'none';
  } catch(e) {}
}

function element_show(element_id) {
  try {
    if (document.layers)
      document.layers[element_id].display = 'block';
    else if (document.all)
      document.all[element_id].style.display = 'block';
    else if (document.getElementById)
      document.getElementById(element_id).style.display = 'block';
  } catch(e) {}
}



function element_enabled(element_id) {
  try {
    if (document.layers)
      document.layers[element_id].disabled = '';
    else if (document.all)
      document.all[element_id].disabled = '';
    else if (document.getElementById)
      document.getElementById(element_id).disabled = '';
  } catch(e) {}
}

function element_disabled(element_id) {
  try {
    if (document.layers)
      document.layers[element_id].disabled = 'disabled';
    else if (document.all)
      document.all[element_id].disabled = 'disabled';
    else if (document.getElementById)
      document.getElementById(element_id).disabled = 'disabled';
  } catch(e) {}
}