$(document).ready(init);

function init(){
    $("#user_firstname").maxlength({ maxChars: 20 });
    $("#user_lastname").maxlength({ maxChars: 20 });
    $("#user_username").maxlength({ maxChars: 20 });
    $("#user_password").maxlength({ maxChars: 20 });
    $("#confirm_password").maxlength({ maxChars: 20 });
}