function clearFields() {
	document.yellow.message.value = '';
}

// 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) {

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

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

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

  
return true;
}