var posX=0;
var posY=0;

function hideTip() { document.getElementById('tip').style.display='none'; show=false; }

function showTip(text)
{
	document.getElementById('tip').innerHTML=text;
	document.getElementById('tip').style.display='block';
	document.getElementById('tip').style.left=posX+'px';
	document.getElementById('tip').style.top=posY-10-document.getElementById('tip').clientHeight+'px';
}

function moveTip(ev)
{
	ev=ev || event;
	posX=ev.x||ev.pageX;
	posY=ev.y||ev.pageY;
}

document.onmousemove=moveTip

function select_all_checkboxes(class_name)
{
  $('.' + class_name).each(function() { this.checked = true; });
  
  return false;
};

function deselect_all_checkboxes(class_name)
{
  $('.' + class_name).each(function() { this.checked = false; });
  
  return false;
};

function invert_all_checkboxes(class_name)
{
  $('.' + class_name).each(function() { this.checked = !this.checked; });
  
  return false;
};