function object(objId)
{
	return document.getElementById(objId);
}


//放大镜
var zoom_m		= 300;	//原图宽
var zoom_mh		= 200;
var zoom_w		= 300;	//显示放大图宽
var zoom_wh		= 200;
var zoom_x		= 90;
var zoom_b		= 600;	//大图宽
var zoom_bh		= 400;
var zoom_x_h	= zoom_x / 2;
var mp_pos		= null;



function getAbsPoint(e)
{
	if (e == null)
	{
		return;
	}
	var x = e.offsetLeft, y = e.offsetTop;
	while (e = e.offsetParent)
	{
		x += e.offsetLeft;
		y += e.offsetTop;
	}
	x = x + 0;
	y = y + 0;
	return {"x": x, "y": y};
}

function locateZoom()
{
	var zw = object("bpd");
	if (zw == null)
	{
		return;
	}

	zw.style.left	= mp_pos.x + zoom_m + 14 + "px";
	zw.style.top	= mp_pos.y + 0 + "px";
}

function slidebp()
{
	var x = event.clientX 
		- mp_pos.x 
		+ document.documentElement.scrollLeft;
	var y = event.clientY 
		- mp_pos.y 
		+ document.documentElement.scrollTop;

	movebigpic(x, y);
	movediv(x, y);

	var mp	= object("mp");
	var bpd	= object("bpd");
	var vpd	= object("vpd");

	if (mp == null || bpd == null || vpd == null)
	{
		return;
	}

	mp.style.filter		= "alpha(opacity=50)";
	bpd.style.display	= "";
	vpd.style.display	= "";
}

function closebp()
{
	var mp = object("mp");
	var bpd = object("bpd");
	var vpd = object("vpd");

	if (mp == null || bpd == null || vpd == null)
	{
		return;
	}

	mp.style.filter		= "";
	bpd.style.display	= "none";
	vpd.style.display	= "none";
}

/* 移动大图 */
function movebigpic(x, y)
{
  var bpd = object("bpd2");
  if (bpd == null)
  {
    return;
  }
  var xx = 0;
  var yy = 0;
  if (x < zoom_x_h)
  {
    xx = 0;
  }
  else if (x > (zoom_m - zoom_x_h))
  {
    xx = zoom_w - zoom_b;	//300-600
  }
  else
  {
    xx = (zoom_x_h - x) * (zoom_b - zoom_w) / (zoom_m - zoom_x);
  }

  if (y < zoom_x_h)
  {
    yy = 0;
  }
  else if (y > (zoom_mh - zoom_x_h))
  {
    yy = zoom_wh - zoom_bh;
  }
  else
  {
    yy = (zoom_x_h - y) * (zoom_bh - zoom_wh) / (zoom_mh - zoom_x);
  }
  bpd.style.left	= xx + "px";
  bpd.style.top		= yy + "px";
}

function movediv(x, y)
{
  var vpd = object("vpd");
  if (vpd == null)
  {
    return;
  }

  var xx = 0;
  var yy = 0;
  if (x < zoom_x_h)
  {
    xx = 0;
  }
  else if (x > (zoom_m - zoom_x_h))
  {
    xx = zoom_m - zoom_x;
  }
  else
  {
    xx = x - zoom_x_h;
  }
  if (y < zoom_x_h)
  {
    yy = 0;
  }
  else if (y > (zoom_mh - zoom_x_h))
  {
    yy = zoom_mh - zoom_x;
  }
  else
  {
    yy = y - zoom_x_h;
  }

  vpd.style.left	= (xx + mp_pos.x) + "px";
  vpd.style.top		= (yy + mp_pos.y) + "px";
  movesmallpic(xx, yy);
}

function movesmallpic(x, y)
{
  var vp = object("vpd2");
  if (vp == null)
  {
    return;
  }

  var xx = 0 - x;
  var yy = 0 - y;

  vp.style.left	= xx + "px";
  vp.style.top	= yy + "px";

}