function show_hide_field(field)
{
  veld = eval("document.getElementById(field).style.display");
  if (veld == 'block')
  {
    eval("document.getElementById(field).style.display = 'none'");
    eval("document.images.img" + field + ".src ='pics/down.gif'");
  }
  else
  {
    eval("document.getElementById(field).style.display = 'block'");
    eval("document.images.img" + field + ".src ='pics/up.gif'");
  }
}
function show_hide_field2(field)
{
  veld = eval("document.getElementById(field).style.display");
  if (veld == 'block')
  {
    eval("document.getElementById(field).style.display = 'none'");
  }
  else
  {
    eval("document.getElementById(field).style.display = 'block'");
  }
}