function _eid(id) {
	return document.getElementById(id);
}

function _eidv(id) {
	var ele = _eid(id);
	return ele.value;
}

function radio_value(base_id) {
	var still_going	= true;
	var count				= 1;
	
	return _eid(base_id+count.toString()).checked;
	
	while(still_going) {
		try {
			if(_eid(base_id+count.toString()).checked)
				return _eidv(base_id+count.toString());
			else
				count++;
		} catch(e) {
			return null;	
		}
	}
}

function null_function() {}
function echo(val) {
	alert(val);
}

function is_enter(function_name, e) {
	if(e && e.keyCode == 13) {
		eval(function_name+'();');
	}
}

function trim(str) {
	var s = new String(str);
	return s.trim();
}

String.prototype.trim = function() {
	return this.replace(/^\s*|\s(?=\s)|\s*$/g, "");
}

function email_validation(email) {
	var filter	= /^([a-zA-Z0-9_\.\-])+\@(([a-zA-Z0-9\-])+\.)+([a-zA-Z0-9]{2,4})+$/;
	
	if(filter.test(email))
		return true;
	else
		return false;
}

function username_validation(username) {
	var filter	= /^([a-zA-Z0-9_\-]{2,25})+$/;
	
	if(filter.test(username))
		return true;
	else
		return false;
}

function password_validation(pwd) {
	var filter	= /^([a-zA-Z0-9_\-]{5,15})+$/;
	
	if(filter.test(pwd))
		return true;
	else
		return false;
}