var MIN = 48;
var MAX = 72;

var img_name = ["accueil", "presentation", "chantiers", "devis", "contact"];
var img = new Array();

var ie = 0;

function preload()
{
  if ((navigator.appVersion.indexOf("MSIE") != -1) && !window.opera)
    ie = 1;
  else
  {
    for (i = 0; i < 5; ++i)
    {
      img[i] = new Image;
      img[i].src = "http://www.atm-plafond-tendu.fr/uploads/images/" + img_name[i] + "_grand.png";
    }
  }
}

function getOffset(el, which)
{
    var amount = 0;

    while (el)
    {
      amount += el[which]
      el = el.offsetParent
    }

    return amount
}

function getX(e)
{
    if (document.all)
    {
        if (document.documentElement)
            return e.clientX + document.documentElement.scrollLeft;
        else
            return e.clientX + document.body.scrollLeft;
    }
    else
        return e.pageX;
}

function getY(e, obj)
{
    if (document.all)
    {
        if (document.documentElement)
            return Math.abs(e.clientY + document.documentElement.scrollTop - getOffset(obj, "offsetTop") - 17);
        else
            return Math.abs(e.clientY + document.body.scrollTop - getOffset(obj, "offsetTop") - 17);
    }
    else
        return Math.abs(e.pageY - getOffset(obj, "offsetTop") - 17);
}

function mouse_enter(e)
{
    var dock = document.getElementById('dock');
    var img_tags = dock.getElementsByTagName('img');

  var header = document.getElementById('header_menu');
    var li = header.getElementsByTagName('li');

    var img_size = [0, 0, 0, 0, 0];
    var att, i, total, val, x, y;

    x = getX(e);
    y = getY(e, header);

    if (y < 17)
        att = 0;
    else
        att = y - 17;

    for (i = 0, total = 0; i < 5; ++i)
    {
    val = MAX - 0.3 * Math.abs((getOffset(li[i], "offsetLeft") + getOffset(li[i + 1], "offsetLeft")) / 2 - x) - att;

    val = Math.round(val);
        if (val < MIN)
            val = MIN;

    if (!ie)
    {
      if (val < 60)
        img_tags[i].src = "http://www.atm-plafond-tendu.fr/uploads/images/" + img_name[i] + "_petit.png";
      else
        img_tags[i].src = "http://www.atm-plafond-tendu.fr/uploads/images/" + img_name[i] + "_grand.png";
    }

        total += val;
        img_size[i] = val;
    }

    document.getElementById('nav_bar').style.width = total + 'px';

    for (i = 0; i < 5; ++i)
    {
        document.getElementById("nav_bar_" + i).style.paddingTop = (MAX - img_size[i]) + 'px';
        img_tags[i].width = img_size[i];
        img_tags[i].height = img_size[i];
    }
}

window.onload = preload;