var bMaximized   = true;
var iLastPage    = 001;
var iLastSubPage = 1;
var sLastPage    = '001'
var baseurl      = 'immagini/';

function changepage()
{
  var sTmp;
  
  if (! bMaximized)
    flip();
    
  if (sLastPage != document.forms[0].pageselect.value)
    delsubpage();
    
  sTmp = baseurl + document.forms[0].pageselect.value;

  if (trim(document.forms[0].subpageselect.value) != '')
  {
    sTmp += '.' + document.forms[0].subpageselect.value;

    iLastSubPage = parseInt(document.forms[0].subpageselect.value);
  }
  else
    iLastSubPage = 1;

  sTmp += '.JPG';

  document.teletext.src = sTmp;

  iLastPage = parseInt(document.forms[0].pageselect.value);
  
  sLastPage = document.forms[0].pageselect.value;
  
  setfocus();
}

function nextpage()
{
  if (iLastPage < 999)
    iLastPage++;
  else
    iLastPage = 001;

  iLastSubPage = 1;

  document.forms[0].pageselect.value    = iLastPage;
  document.forms[0].subpageselect.value = '';

  changepage();
}

function prevpage()
{
  if (iLastPage > 001)
    iLastPage--;
  else
    iLastPage = 999;

  iLastSubPage = 1;

  document.forms[0].pageselect.value    = iLastPage;
  document.forms[0].subpageselect.value = '';

  changepage();
}

function nextsubpage()
{
  if (iLastSubPage < 99)
    iLastSubPage++;
  else
    iLastSubPage = 1;

  if (iLastSubPage == 1)
    document.forms[0].subpageselect.value = '';
  else
    document.forms[0].subpageselect.value = iLastSubPage;

  changepage();
}

function prevsubpage()
{
  if (iLastSubPage > 1)
    iLastSubPage--;
  else
    iLastSubPage = 99;

  if (iLastSubPage == 1)
    document.forms[0].subpageselect.value = '';
  else
    document.forms[0].subpageselect.value = iLastSubPage;

  changepage();
}

function mainpage()
{
  iLastPage    = 100;
  iLastSubPage = 1;

  document.forms[0].pageselect.value    = iLastPage;
  document.forms[0].subpageselect.value = '';

  changepage();
}

function nosubmit()
{
  changepage();

  return false;
}

function setfocus()
{
  document.forms[0].pageselect.focus();
  document.forms[0].pageselect.select();
}

function delsubpage()
{
  iLastSubPage = 1;

  document.forms[0].subpageselect.value = '';
}

function flip()
{
  if (bMaximized)
  {
  	document.getElementById('mainView').style.height = '56px';
  	document.getElementById('content').style.visibility = 'hidden';
  }
  else
  {
  	document.getElementById('mainView').style.height = '512px';
  	document.getElementById('content').style.visibility = 'visible';
  }
  
  bMaximized = ! bMaximized;
  
  setfocus();
}

function minimize()
{
  if (bMaximized)
    flip();
  else
    setfocus();
}

function maximize()
{
  if (! bMaximized)
    flip();
  else
    setfocus();
}

function trim(str) {
   return str.replace(/^\s*|\s*$/g, "");
}