var tid; 
var left;
var top;
var default_stepsize=1;
function initScroller() {
  if (parent.main.document.layers)
  {
    left = parent.main.document.contentarea.left;
    top = parent.main.document.contentarea.top;
  }
  else if (parent.main.document.all)
  {
    left = parent.main.document.all.contentarea.offsetLeft;
    top = parent.main.document.all.contentarea.offsetTop;
  }
  else if (parent.main.document.getElementById)
  {
    left = parent.main.document.getElementById('contentarea').offsetLeft;
    top = parent.main.document.getElementById('contentarea').offsetTop;
  }
}
function moveLeft (stepsize) {
  if (typeof left == 'undefined') 
    initScroller();
  if (typeof stepsize == 'undefined')
  {	left -= default_stepsize;
  } else
  {	left -= stepsize;
  }
  if (parent.main.document.layers)
    parent.main.document.contentarea.left = left;
  else if (parent.main.document.all)
    parent.main.document.all.contentarea.style.pixelLeft = left;
  else if (parent.main.document.getElementById)
    parent.main.document.getElementById('contentarea').style.left = left + 'px';
}
function moveRight (stepsize) {
  if (typeof left == 'undefined') 
    initScroller();
  if (typeof stepsize == 'undefined')
  {	left += default_stepsize;
  } else
  {	left += stepsize;
  }
  if (parent.main.document.layers)
    parent.main.document.contentarea.left = left;
  else if (parent.main.document.all)
    parent.main.document.all.contentarea.style.pixelLeft = left;
  else if (parent.main.document.getElementById)
    parent.main.document.getElementById('contentarea').style.left = left + 'px';
}
function moveUp (stepsize) {
  if (typeof left == 'undefined') 
    initScroller();
  if (typeof stepsize == 'undefined')
  {	top -= default_stepsize;
  } else
  {	top -= stepsize;
  }
  if (parent.main.document.layers)
    parent.main.document.contentarea.top = top;
  else if (parent.main.document.all)
    parent.main.document.all.contentarea.style.pixelTop = top;
  else if (parent.main.document.getElementById)
    parent.main.document.getElementById('contentarea').style.top = top + 'px';
}
function moveDown (stepsize) {
  if (typeof left == 'undefined') 
    initScroller();
  if (typeof stepsize == 'undefined')
  {	top += default_stepsize;
  } else
  {	top += stepsize;
  }
  if (parent.main.document.layers)
    parent.main.document.contentarea.top = top;
  else if (parent.main.document.all)
    parent.main.document.all.contentarea.style.pixelTop = top;
  else if (parent.main.document.getElementById)
    parent.main.document.getElementById('contentarea').style.top = top + 'px';
}