function $(id){return document.getElementById(id)};
    
    function check_comment(){
        var err = 0;
        var errmsg = $('commentError');
        var email = $('commentform').email;
        var author = $('commentform').author;
        var comment = $('commentform').comment;
        try {
            clear_errors();
            if(author != null && author.value.length <= 0){ author.style.borderColor = 'red'; err++; }
            if(email != null && email.value.length <= 0){ email.style.borderColor = 'red'; err++; }
            if(comment != null && comment.value.length <= 0){ comment.style.borderColor = 'red'; err++; }
            if(err > 0){ errmsg.innerHTML = 'Please fill in all required fields.'; }
            else {
                if((email == null) || email.value.indexOf('@') > 0 &&  email.value.indexOf('.') > 0){ $('commentform').submit(); }
                else { errmsg.innerHTML = 'Please enter a valid email address.'; email.style.borderColor = 'red'; }
            }
        } catch(e){}
    }
    
    function clear_errors(){
        try {
            $('commentform').author.style.border = $('commentform').email.style.border = $('commentform').comment.style.border = '1px solid #b6b6b6';
            $('commentError').innerHTML = '';
        } catch(e){}
    }