var lp_div_kosz = document.createElement('div');
    var tx = document.createTextNode(l_p)
    Page_updater.appendChild(lp_div_kosz, tx);
    
    var nazwa_a_kosz = document.createElement('a');
    var tx2 = document.createTextNode(nazwa_kosz);
    Page_updater.appendChild(nazwa_a_kosz, tx2);
    
    var cena_div_kosz = document.createElement('div');
    var tx3 = document.createTextNode(cena_kosz);
    Page_updater.appendChild(cena_div_kosz, tx3);
    
    var usun_prod_ico = Page_updater.createElement('form', {action:''});
    var form_div1 = document.createElement('div');
    var usun_but = Page_updater.createNoEndTagElement('input', {type:'button', Class:'remove_ico', value:'', onclick:'javascript:Koszyk.usun(this.parentNode);'});
    Page_updater.appendChild(form_div1, usun_but);
    Page_updater.appendChild(usun_prod_ico, form_div1);
    
    var change_quant = Page_updater.createElement('form', {action:'', id:'ch_f_prod'+id_kosz});
    var form_div2 = document.createElement('div');
    var change_inp = Page_updater.createNoEndTagElement('input', {type:'text', Class:'change_quant', value:ilosc_kosz, onblur:'javascript:Koszyk.zmien_ilosc(this.parentNode, this.value);'});
    Page_updater.appendChild(form_div2, change_inp);
    Page_updater.appendChild(change_quant, form_div2);

Page_updater.removeChild = function()
{
    if(this.removeChild.arguments.length = 1)
    {
        var argum = document.getElementById(this.removeChild.arguments[0]);
        for(var i = 0; i < argum.childNodes.length; i++)
        {
            if(argum.childNodes.item(i))
            {
                argum.removeChild(argum.childNodes.item(i));
            }
        }
        return argum;
    }
    else
    {
        return null;
}

[HTML] pobierz, plaintext 
<div id='prod1'>
  <div>1</div>
  <a>costamcostam</a>
  <div>120.00</div>
  <form>
    <div>
      <input ..... />
    </div>
  </form>
</div>
[HTML] pobierz, plaintext 

for(var i = 0; i < argum.childNodes.length; i++)
{
   if(argum.childNodes.item(i))
   {
      argum.removeChild(argum.childNodes.item(i));
   }
}

var count = argum.childNodes.length;
for(var i = count; i > 0; i--)
    argum.removeChild(argum.childNodes.item(i-1));

Page_updater.removeChild = function()
{
    if(this.removeChild.arguments.length = 1)
    {
        var argum = document.getElementById(this.removeChild.arguments[0]);
        var count = argum.childNodes.length;
        for(var i = count; i >= 0; i--)
        {
            if(argum.childNodes[i])
            {
                argum.removeChild(argum.childNodes[i]);
            }
        }
        return argum;
    }
    else
    {
        return null;
        }
}