function getId(id)
{
  return document.getElementById(id);
}

function value_show(input, value)
{
  if (input.value == '') input.value = value;
}

function value_hide(input, value)
{
  if (input.value == value) input.value = '';
}

function show(photo, w, h)
{
  var doc = document.documentElement;
  var win = document.getElementById("img_win");
  var img = document.getElementById("img");

  var border = 10;
  var d_w = doc.clientWidth - border;
  var d_h = doc.clientHeight - border;

  if (w > d_w)
  {
    k = w / d_w;
    w = d_w;
    h = Math.round(h / k);
  }

  if (h > d_h)
  {
    k = h / d_h;
    h = d_h;
    w = Math.round(w / k);
  }

  var top = doc.clientHeight/2 - h/2 - border/2 + "px";
  if (top < 0) top = 0;
  win.style.top = top;
  win.style.left =  Math.round(doc.clientWidth/2 - w/2 - border/2) + "px";

  img.width = w;
  img.height = h;
  img.src = photo;

  win.style.visibility = "visible";
}

function hide()
{
  document.getElementById("img_win").style.visibility = "hidden";
  document.getElementById("img").src = "/img/1x1.gif";
}

function empty(form, field, mes)
{
  var el = document.forms[form].elements[field];
  if (el.value == "" || el.value == mes)
  {
    alert('Введите ' + mes + '!');
    return false;
  }
  else return true;
}

function mail_send()
{
  var war = new Array('Имя', 'E-mail', 'Телефон', 'Сообщение');
  for (i=0; i<war.length; i++) if (!empty('mail', i, war[i])) return false;

  var email = document.mail.elements[1];
  var r = /.{1,}@.{1,}(\.[a-z]{2,4})+/;
  if (!r.test(email.value))
  {
    alert('Неправильно введен E-mail!');
    return false;
  }
}

function textarea()
{
  var el = document.mail.elements[2];
  if (el.value.length > 1000) el.value = el.value.substring(0, 1000);
}

function order_sh(sel)
{
  var shadow = getId("shadow");
  var order_win = getId("order_win");
  var select = document.order.elements[3];

  if (sel == undefined)
  {
    shadow.style.visibility = "hidden";
    order_win.style.visibility = "hidden";
  }
  else
  {
    shadow.style.visibility = "visible";
    order_win.style.visibility = "visible";
    select.options[sel].selected = true;
  }
}

function order_send()
{
  var war = new Array('Имя', 'E-mail', 'Телефон', '', 'Сообщение');
  for (i=0; i<war.length; i++) if (!empty('order', i, war[i])) return false;

  var email = document.order.elements[1];
  var r = /.{1,}@.{1,}(\.[a-z]{2,4})+/;
  if (!r.test(email.value))
  {
    alert('Неправильно введен E-mail!');
    return false;
  }
}