function toggle_elem( id )
{
 var elem = document.getElementById( id );
 var stav = elem.style.display;
 
 if ( stav == 'none' ) elem.style.display = 'block';
 else elem.style.display = 'none';
}

function toggle_data( id, val1, val2 )
{
 var elem = document.getElementById( id );
 var stav = elem.value;

 if ( stav == val1 ) elem.value = val2;
 else elem.value = val1;
}

function prepocitaj_cenu( id_radio, id_result, cena, cena_orig, id_postovne )
{
 var postovne = document.getElementById( id_radio ).value;
 var result = document.getElementById( id_result );
 var typ_postovne = document.getElementById( 'typ_postovne' );
 
 typ_postovne.value = id_postovne;

 cena_celkom = ( cena * 1 ) + ( postovne * 1 );
 result.innerHTML = cena_celkom.toFixed(2) + '€';
 
 if ( cena_orig > 0 )
 {
   var orig_result = document.getElementById( 'cena_orig' );

   orig_celkom = ( cena_orig * 1 ) + ( postovne * 1 );
   orig_result.innerHTML = orig_celkom.toFixed(2) + '€';
 }

 
}