function $(id) {
	if(document.all) {
		element = eval("document.all."+id);
	} else {
		element = document.getElementById(id);
	}
	return element;
}
var myrules = {
		'#age_form input' : function(element){
			element.onfocus = function(){
				this.value = "";
			}
		},
		'#age_day' : function(element){
			element.onkeyup = function(){
				if(this.value.length == this.size) $('age_month').focus();
			}
		},
		'#age_month' : function(element){
			element.onkeyup = function(){
				if(this.value.length == this.size) $('age_year').focus();
			}
		},
		'#age_year' : function(element){
			element.onkeyup = function(){
				if(this.value.length == this.size) $('age_submit').focus();
			}
		}
	};
	
	Behaviour.register(myrules);