function contact_form_prefered(id) {

	id = document.getElementById(id);

    if (id.pref_kontakt.value == "0") {
        id.tel.className = "A_required A_digit";
        id.email.className = "A_email";
    }
    if (id.pref_kontakt.value == "1") {
        id.email.className = "A_required A_email";
        id.tel.className = "A_digit";
    }

}


function sh_selects() {
	for (var current_element, current_type, ref = document.getElementById('form_konfigurator').elements, i = 0, i_length = ref.length; i < i_length; i++) {
		current_element = ref[i];
		current_element_class = current_element.className;

		if (current_element_class != "") {
			sh_check_field(ref, current_element, current_element_class.split(" "));
		}
	}

	return true;

}
function sh_check_field(ref, field, rules) {
	for (var current_rule, current_length, i = 0, i_length = rules.length; i < i_length; i++) {
		current_rule = rules[i];

		switch (current_rule) {

			// kontrola pola na vyplnenie - povinne pole
			case "sh_select":

			 field.className = 'sh_select_hidden'
			break;
			
			case "sh_select_hidden": 
			 field.className = 'sh_select'
			break;
			
			
		}
	}
}