function selectedPaese()
{
	var selected_index = document.form.elements['paese'].selectedIndex;
	
	var selected_option_value = document.form.elements['paese'].options[selected_index].value;
	
	if(selected_option_value==999){
		document.form.elements['altro_paese'].disabled=false;
	}else{
		document.form.elements['altro_paese'].disabled=true;
	}
}