function disableSlalomAgeGroupSelect(){
	var race      = document.getElementById("race");
	var age_group = document.getElementById("age_group");
	var hidden    = document.getElementById("hidden_age_group");
	if(race.length >= 2) race.remove(2);
	if((race.value == "Fun Dual Slalom") || (race.value == "10km")){
	  age_group.selectedIndex = 0;
		hidden.value = "all";
		age_group.disabled = true;
	}else{
	 		age_group.disabled = false;
 }
}

window.onload = disableSlalomAgeGroupSelect;