function validateFields(form_id) {
    
    var form = $(form_id);
	var errorBox = $('form_errors');
    var errors = new Array();
	
    $A(form.getElementsByClassName('required')).each(
       function(node) {
           if (node.value.length == 0) {
               node.style.border = "1px solid red";
               errors.push(node.name);
           } else {
               node.style.border = "1px solid #7f9db7";
           }
       }
    );
	var anyChecked = false;
    $A(form.getElementsByClassName('onerequired')).each(
       function(node) {
           if (node.checked) {
               anyChecked = true;
           }
       }
    );
	if(!anyChecked) {
		errors.push("Ainakin yksi aihe yhteydenotollesi")
		$('subjects').style.border = "1px solid red";
	} else {
		$('subjects').style.border = "";
	}
    
    if (errors.length > 0) {
		/*window.scrollTo(0,0);*/
        alert('Seuraavat kentät ovat pakolliset:\n- ' + errors.join("\n- "));
		return false;
    } else {
        form.submit();
		return true;
    }
	
}