function setObjPosition(obj2repID, objBaseID)
{
  _sopObj1 = document.getElementById(obj2repID);
  _sopObj2 = document.getElementById(objBaseID);
  if (_sopObj1 && _sopObj2)
  {
      bsc = _sopObj2;
      x   = _sopObj2.offsetLeft;
      y   = _sopObj2.offsetTop;
     // if (isGecko)
     //     y -= 15;
      while (bsc = bsc.offsetParent)
      {
         x += bsc.offsetLeft;
         y += bsc.offsetTop;
      }
      _sopObj1.style.position = 'absolute';
      _sopObj1.style.left     = x+'px';
      _sopObj1.style.top      = y+'px';
      _sopObj1.style.display  = 'none';
      _sopObj1.style.zIndex   = 100;
  }
}

var price_obj = false;
var ch_st_obj = false;
var ch_lbst_obj = false;
var legz_obj = false;

function changePrice(id)
{
    if (!price_obj)
        price_obj = document.getElementById("displPrice");
    if (!ch_st_obj)
        ch_st_obj = document.getElementById("student");
    if (!ch_lbst_obj)
        ch_lbst_obj = document.getElementById("lb_student");
    if (!legz_obj)
        legz_obj = document.getElementById("sztuk");
    prInd = 0;

    if (id===false)
    {
       _okr = document.getElementsByName('okres');
       if (_okr)
       {
          for (i=0; i<_okr.length; i++)
          {
             if (_okr[i].checked)
             {
                changePrice(_okr[i].id.replace("okres_", ""));
                return
             }
          }
       }
    }
    if ((ch_st_obj)&&(id != false))
    {
        if (prices[id][1]==0)
           ch_st_obj.setAttribute('disabled','disabled');
        else
        {
           ch_st_obj.removeAttribute('disabled');
           if (ch_st_obj && (ch_st_obj.checked))
               prInd = 1;
        }
    }
    if ((ch_lbst_obj)&&(id != false))
    {
        if (prices[id][1]==0)
           ch_lbst_obj.setAttribute('disabled','disabled');
        else
           ch_lbst_obj.removeAttribute('disabled');
    }
    if ((price_obj)&&(id != false))
    {
        if (prices[id][prInd])
        {
            do_zaplaty = prices[id][prInd];
            if (prInd==1)
                waluta = 'zł';
            else
            {
                waluta = prices[id][2];
                do_zaplaty_to_pln = prices[id][3];
            }
            if (legz_obj)
            {
                do_zaplaty = do_zaplaty * legz_obj.value;   
                if (waluta != 'zł')   
                    do_zaplaty_to_pln = do_zaplaty_to_pln * legz_obj.value;  
            }
            if (waluta == 'zł')
                price_obj.innerHTML = 'do zapłaty <span>'+do_zaplaty+' '+waluta+'</span>';
            else
            if (do_zaplaty_to_pln)
                price_obj.innerHTML = 'do zapłaty <span>'+do_zaplaty+' '+waluta+'<br /><small>'+do_zaplaty_to_pln.toFixed(2)+' zł</small></span>';
        }
        else
            price_obj.innerHTML = '';
    }
}