/**
* Return true if the argument is a valid user name
*/
var MIN_LEN = 4;
var MAX_LEN = 20;
function is_valid_user_name(n) {
	if ( n == null )
		return false;
	if ( n.length < MIN_LEN || n.length > MAX_LEN )
		return false;
	var reg = /[^A-Za-z0-9_]/;
	if ( reg.exec(n) )
		return false;
	return true;
}

/**
* Return true if the argument is a valid password
*/
function is_valid_password(p) {
	return is_valid_user_name(p);
}

//From http://developer.irt.org/script/241.htm
function stripSpaces(x) {
    while (x.substring(0,1) == ' ') x = x.substring(1);
    while (x.substring(x.length-1,x.length) == ' ') x = x.substring(0,x.length-1);
    return x;
}

//Return a DOM ref to an object
function get_obj_ref ( obj_name ) {
	if ( document.all )
		obj_ref = document.all(obj_name);
	else
		obj_ref = document.getElementById(obj_name);
	return obj_ref;
}