Designing with JavaScript CD Code

<HTML>
<HEAD><TITLE>Send Us Mail</TITLE>
<SCRIPT LANGUAGE = "JavaScript">
<!--

// 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?

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

    // is fullname element filled?

    if (isFilled(form.fullname) == false) {
    alert("Please enter your name.");
    form.fullname.focus();
    return false;
    }

    // is opinion element filled?

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

//-->
</SCRIPT>
</HEAD>
<BODY BGCOLOR = "#FFFFFF">
<FORM NAME = "mailform" onSubmit = "return isReady(this)" ACTION = "cgi-bin/mailform.cgi">
your name: <INPUT NAME = "fullname" TYPE = TEXT>
your email: <INPUT NAME = "address" TYPE = TEXT>
<P>your opinion:<P><TEXTAREA NAME = "opinion" ROWS = 6 COLS = 64 WRAP></TEXTAREA>
<P><INPUT TYPE = SUBMIT VALUE = " S e n d ">
<INPUT TYPE = RESET VALUE = " T r a s h ">
</FORM>
</BODY>
</html>