function getyScroll()
 {
  yScroll = 0;

  if (window.innerHeight && window.scrollMaxY || window.innerWidth && window.scrollMaxX)
   {
    yScroll = window.innerHeight + window.scrollMaxY;
    xScroll = window.innerWidth + window.scrollMaxX;

    var deff = document.documentElement;
    var wff = (deff&&deff.clientWidth) || document.body.clientWidth || window.innerWidth || self.innerWidth;
    var hff = (deff&&deff.clientHeight) || document.body.clientHeight || window.innerHeight || self.innerHeight;

    xScroll -= (window.innerWidth - wff);
    yScroll -= (window.innerHeight - hff);
   } 
  else if (document.body.scrollHeight > document.body.offsetHeight || document.body.scrollWidth > document.body.offsetWidth)
   { // all but Explorer Mac
    yScroll = document.body.scrollHeight;
    xScroll = document.body.scrollWidth;
   } 
  else 
   { // Explorer Mac...would also work in Explorer 6 Strict, Mozilla and Safari
    yScroll = document.body.offsetHeight;
    xScroll = document.body.offsetWidth;
   }

  return yScroll;
 }

function showloginform()
 {
  $('niceloginform').style.display = 'block';
  $('niceloginform').scrollIntoView(true);
  $('screen').style.display = 'block';
  $('screen').style.height = getyScroll() + 'px'; //window.innerHeight + window.scrollMaxY;
  $('screen').onclick=hideloginform;
  return false;
}

function hideloginform()
 {
  $('niceloginform').style.display = 'none';
  $('screen').style.display = 'none';
 }


function showneedloginform()
 {
  $('needloginform').style.display = 'block';
  $('needloginform').scrollIntoView(true);
  $('screen').style.display = 'block';
  $('screen').style.height = getyScroll() + 'px'; //window.innerHeight + window.scrollMaxY;
  $('screen').onclick=hideneedloginform;
  return false;
}

function hideneedloginform()
 {
  $('needloginform').style.display = 'none';
  $('screen').style.display = 'none';
 }