function Recount(theform) {
var celkcena = 0	
	for(var i=1; i<=100; i++) {
	  if (theform.elements["f_" + i + "_thuja_kusu"]) {
      el = document.getElementById("f_" + i + "_thuja_kc");
	    celkcena += Number(el.value);
	  }
	}
	theform.f_suma_kc.value = celkcena;
}