var f = document.f2;
f.elements[i].options[Math.floor((f.elements[i].length-1)*Math.random())+1].selected=true;

 function sf2() {
  var f = document.f2;
  for(i=0;i<f.elements.length;i++) {
   if(f.elements[i].type==’text’)
    f.elements[i].value = ‘test’;
  }
 }

<input name=”fld_katalog” type=”text” id=”fld_katalog” value=”2008_08_14″ disabled>

<input name=”fld_zmien” type=”button” value=”Odblokuj” class=”przycisk” onclick=”this.form.elements['fld_katalog'].disabled = false;”>

var fld_cecha_name = „cecha_”+tab_nr+”_”+nr;

fld_cecha = form.elements[fld_cecha_name];
fld_cecha.value = „”;
fld_cecha.disabled = false;

var fld_name;
var idx, nr;
cnt = f.elements.length;

for(i=0; i<cnt; i++){
 if(f.elements[i].name.indexOf(„kwota_budzetu_”)!=-1) {
  fld_name = f.elements[i].name;
  idx = fld_name.lastIndexOf(„_”)+1;
  nr = fld_name.substr(idx);

  f.elements["roznica_proj_"+nr].value =
   eval(f.elements["kwota_budzetu_"+nr].value) -
   eval(f.elements["wartosc_proj_"+nr].value);
 }
}

function suma_oblicz(f) {

    cnt = f.elements.length;
    suma = 0;
   
    for(i=0; i<cnt; i++){
        if(f.elements[i].name.indexOf(„kwota_budzetu_”)!=-1)
        suma += eval(f.elements[i].value);
    }

    f.elements["suma_kwota_budzetu"].value = suma;
}

function odznacz(form, fld_name)
{
    fld = form.elements[fld_name];
    len = fld.length

    for(i=0; i<len; i++)
    {
        if(fld.options[i].selected)
            fld.options[i].selected = false;
    }
}