找一个元素的坐标

function findPosition(oElement) 
{
  var x2 = 0;
  var y2 = 0;
  var width = oElement.offsetWidth;
  var height = oElement.offsetHeight;
  //alert(width + "=" + height);
  if( typeof( oElement.offsetParent ) != 'undefined' ) 
  {
    for( var posX = 0, posY = 0; oElement; oElement = oElement.offsetParent ) 
    {
      posX += oElement.offsetLeft;
      posY += oElement.offsetTop;      
    }
    x2 = posX + width;
    y2 = posY + height;
    return [ posX, posY ,x2, y2];
    
    } else{
      x2 = oElement.x + width;
      y2 = oElement.y + height;
      return [ oElement.x, oElement.y, x2, y2];
  }
}