function toggleDiv(div_id)
{
  if (document.getElementById(div_id))
  {
    if (document.getElementById(div_id).style.display == 'none')
      document.getElementById(div_id).style.display = 'block';
    else
      document.getElementById(div_id).style.display = 'none';
  }
}


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


function clearForm(form_id)
{
  form = document.getElementById(form_id);
  
  for (k = 0; k < form.elements.length; k++)
  {
    element = form.elements[k];

    switch (element.type)
    {
      case 'text' :
      case 'textarea' :
        element.value = '';
        break;
      
      case 'radio' :
      case 'checkbox' :
        element.checked = '';
        break;
      
      case 'select-one' :
        element.selectedIndex = 0;
        break;
      
      case 'select-multiple' :
        for (var m = 0; m < element.options.length; m++)
        {
          element.options[m].selected = false;
        }
        break;
    }
  }
}