function validateFeedback() {
    if (document.feedback.email.value !="") {
	    var email=document.feedback.email.value;
	    if (email.indexOf(' ')==-1 && 0<email.indexOf('@') && email.indexOf('@')+3 < email.length && 0<email.indexOf('.') && email.indexOf('.')+1 < email.length) {
		    //Check for web-based emails
		    if (checkValidEmail(email) > 0) {
			    alert('You have entered an invalid email address!  Please use your work email address and use valid characters.');
			    document.feedback.email.select();
			    document.feedback.email.focus();
			    return false;
		    }
	    } else {
		    alert ('You have entered an invalid email address!')
		    document.feedback.email.focus();
		    return false;
	    }
    } else {
	    alert("Please enter an email address");
	    document.feedback.email.focus();
	    return false;
    }
    
    $('input[type=submit]').attr('disabled', 'disabled');

    return (true);
}