function resizediv() {
var lewa = document.getElementById('lewa');
var srodek = document.getElementById('srodek');
var prawa = document.getElementById('prawa');
if(lewa != null && srodek != null && prawa != null) {
lewa_wysokosc = lewa.offsetHeight;
srodek_wysokosc = srodek.offsetHeight;
prawa_wysokosc = prawa.offsetHeight;
	if(lewa_wysokosc < srodek_wysokosc)
      {
      	if(prawa_wysokosc < srodek_wysokosc)
            {
      		lewa.style.height = (srodek_wysokosc + 0) + "px";
      		prawa.style.height = (srodek_wysokosc + 0) + "px";
      	}
	      else
	      {
	            lewa.style.height = (prawa_wysokosc + 0) + "px";
      		srodek.style.height = (prawa_wysokosc + 0) + "px";
	      }
      }
      else
      {
     	      if(prawa_wysokosc < lewa_wysokosc)
            {
      		srodek.style.height = (lewa_wysokosc + 0) + "px";
      		prawa.style.height = (lewa_wysokosc + 0) + "px";
      	}
	      else
	      {
	            lewa.style.height = (prawa_wysokosc + 0) + "px";
      		srodek.style.height = (prawa_wysokosc + 0) + "px";
	      }
      }
}
}
/*
window.onload = function() {
  document.onselectstart= function() { return false; } // ie
  document.onmousedown  = function() { return false; } // mozilla
}
*/
function zmien_zdjecie(obrazek) {
  document.getElementById("obrazek_glowny").src=obrazek;
  document.getElementById("link_glowny").href=obrazek;
}
function displayWindow(url, width, height) {
        var Win = window.open(url,"displayWindow",'width=' + width + ',height=' + height + ',resizable=0,scrollbars=no,menubar=no' );
}
function drukuj(){
   j = parseInt(navigator.appVersion)
   if (j >= 4) window.print()
}
function mail() {
	location.href='mailto:?SUBJECT=Polecam produkt &BODY=Zobacz produkt pod adresem:' + escape(location.href)
	window.location.href
	}
function showhide(id){
if (document.getElementById){
obj = document.getElementById(id);
if (obj.style.display == "none"){
obj.style.display = "";
} else {
obj.style.display = "none";
}
}
}
function showhidesub(id,id2){
if (document.getElementById){
obj = document.getElementById(id);
obj2 = document.getElementById(id2);
if (obj.style.display == "none"){
obj.style.display = "";
obj2.innerHTML = '-';
} else {
obj.style.display = "none";
obj2.innerHTML = '+';
}
}
}
<!--
function setPointer(theRow, thePointerColor)
{
    if (thePointerColor == '' || typeof(theRow.style) == 'undefined') {
        return false;
    }
    if (typeof(document.getElementsByTagName) != 'undefined') {
        var theCells = theRow.getElementsByTagName('td');
    }
    else if (typeof(theRow.cells) != 'undefined') {
        var theCells = theRow.cells;
    }
    else {
        return false;
    }

    var rowCellsCnt  = theCells.length;
    for (var c = 0; c < rowCellsCnt; c++) {
        theCells[c].style.backgroundColor = thePointerColor;
    }

    return true;
}

/***********************************************
* Highlight Table Cells Script- © Dynamic Drive DHTML code library (www.dynamicdrive.com)
* Visit http://www.dynamicDrive.com for hundreds of DHTML scripts
* This notice must stay intact for legal use
***********************************************/

//Specify highlight behavior. "TD" to highlight table cells, "TR" to highlight the entire row:
//var highlightbehavior="TR"

var ns6=document.getElementById&&!document.all
var ie=document.all

function changeto(e,highlightcolor,highlightbehavior){
source=ie? event.srcElement : e.target
if (source.tagName=="TABLE")
return
while(source.tagName!=highlightbehavior && source.tagName!="HTML")
source=ns6? source.parentNode : source.parentElement
if (source.style.backgroundColor!=highlightcolor&&source.id!="ignore")
source.style.backgroundColor=highlightcolor
}

function contains_ns6(master, slave) { //check if slave is contained by master
while (slave.parentNode)
if ((slave = slave.parentNode) == master)
return true;
return false;
}

function changeback(e,originalcolor){
if (ie&&(event.fromElement.contains(event.toElement)||source.contains(event.toElement)||source.id=="ignore")||source.tagName=="TABLE")
return
else if (ns6&&(contains_ns6(source, e.relatedTarget)||source.id=="ignore"))
return
if (ie&&event.toElement!=source||ns6&&e.relatedTarget!=source)
source.style.backgroundColor=originalcolor
}

function MM_swapImgRestore() { //v3.0
  var i,x,a=document.MM_sr; for(i=0;a&&i<a.length&&(x=a[i])&&x.oSrc;i++) x.src=x.oSrc;
}

function MM_preloadImages() { //v3.0
  var d=document; if(d.images){ if(!d.MM_p) d.MM_p=new Array();
    var i,j=d.MM_p.length,a=MM_preloadImages.arguments; for(i=0; i<a.length; i++)
    if (a[i].indexOf("#")!=0){ d.MM_p[j]=new Image; d.MM_p[j++].src=a[i];}}
}

function MM_findObj(n, d) { //v4.01
  var p,i,x;  if(!d) d=document; if((p=n.indexOf("?"))>0&&parent.frames.length) {
    d=parent.frames[n.substring(p+1)].document; n=n.substring(0,p);}
  if(!(x=d[n])&&d.all) x=d.all[n]; for (i=0;!x&&i<d.forms.length;i++) x=d.forms[i][n];
  for(i=0;!x&&d.layers&&i<d.layers.length;i++) x=MM_findObj(n,d.layers[i].document);
  if(!x && d.getElementById) x=d.getElementById(n); return x;
}

function MM_swapImage() { //v3.0
  var i,j=0,x,a=MM_swapImage.arguments; document.MM_sr=new Array; for(i=0;i<(a.length-2);i+=3)
   if ((x=MM_findObj(a[i]))!=null){document.MM_sr[j++]=x; if(!x.oSrc) x.oSrc=x.src; x.src=a[i+2];}
}
//-->
<!--
function displayWindow(url, width, height) {
        var Win = window.open(url,"displayWindow",'width=' + width + ',height=' + height + ',resizable=no,scrollbars=yes,menubar=no' );

}
//-->
<!--
function LmOver(elem, clr)
{elem.style.backgroundColor = clr;
elem.children.tags('A')[0].style.color = "#FFFFFF";
elem.style.cursor = 'hand'}

function LmOut(elem, clr)
{elem.style.backgroundColor = clr;
elem.children.tags('A')[0].style.color = "#CC3300";}

function LmDown(elem, clr)
{elem.style.backgroundColor = clr;
elem.children.tags('A')[0].style.color = "#FFFFFF";}

function LmUp(path)
{location.href = path;}
//-->
function goback() {
    history.go(-1);
}

<!-- zmienia styl klas -->
function zmienKlase(paraCSS,zmiana) {

document.getElementById('srodek').style[paraCSS] = zmiana;
document.getElementById('srodek').style['lineHeight'] = zmiana;

obj = document.getElementsByClassName('losowy_tekst');
for(i=0; i < obj.length; i++) {
obj[i].style[paraCSS] = zmiana;
obj[i].style['lineHeight'] = zmiana;
}

obj = document.getElementsByClassName('szukajopis');
for(i=0; i < obj.length; i++) {
obj[i].style[paraCSS] = zmiana;
obj[i].style['lineHeight'] = zmiana;
}

obj = document.getElementsByClassName('szukajtytullink');
for(i=0; i < obj.length; i++) {
obj[i].style[paraCSS] = zmiana;
obj[i].style['lineHeight'] = zmiana;
}

obj = document.getElementsByClassName('up');
for(i=0; i < obj.length; i++) {
obj[i].style[paraCSS] = zmiana;
obj[i].style['lineHeight'] = zmiana;
}

obj = document.getElementsByClassName('back');
for(i=0; i < obj.length; i++) {
obj[i].style[paraCSS] = zmiana;
obj[i].style['lineHeight'] = zmiana;
}

obj = document.getElementsByClassName('krotkiopis_akt');
for(i=0; i < obj.length; i++) {
obj[i].style[paraCSS] = zmiana;
obj[i].style['lineHeight'] = zmiana;
}

obj = document.getElementsByClassName('tresc_form');
for(i=0; i < obj.length; i++) {
obj[i].style[paraCSS] = zmiana;
obj[i].style['lineHeight'] = zmiana;
}

}