function checkAll(form_name, checkbox_name, checked) {
	var form = document.getElementById(form_name);

	if (form[checkbox_name + "[]"].length == undefined) {
		form[checkbox_name + "[]"].checked = checked;
	} else {
		for(i = 0; i < form[checkbox_name + "[]"].length; i++){
			form[checkbox_name + "[]"][i].checked = checked;
		}
	}
}