function alertX(x)
{
 if(!x)
 	{
  	document.getElementById('alertX').style.visibility='hidden'
  	return
 	}
 with(document.getElementById('alertX'))
 {
  style.height='';innerHTML=x+
  '<hr class=c><div style="text-align:center">'+
  '<a href="javascript:alertX()">Zamknij</a></div>'
  var y=window.innerHeight?innerHeight:document.body.clientHeight,
  m=y-50
  style.height=offsetHeight>m?m+'px':''
  style.bottom=y/2-offsetHeight/2+'px'
  style.visibility='visible'
  }
}