// Check for email address: look for [@] and [.] 

function isEmail(elm) {
    if (elm.value.indexOf("@") + "" != "-1" &&
        elm.value.indexOf(".") + "" != "-1" &&
        elm.value != "") 
    return true;
    else return false;
}

// Check for null and for empty

function isFilled(elm) {
    if (elm.value == "" ||
        elm.value == null) 
    return false;
    else return true;
}

function isReady(form) {

    // is address element a real email address?

    
    // is fullname element filled?

    if (isFilled(form.author) == false) {
    alert("Please enter your name.");
    form.author.focus();
    return false;
    }
    
    if (isEmail(form.email) == false) { 
    alert("Please enter your email address.");
    form.email.focus();
    return false;
    }

    // is opinion element filled?

    if (isFilled(form.comment) == false) {
    alert("Please enter your message.");
    form.comment.focus();
    return false;
    }
return true;
}