YAHOO.util.Event.addListener('emailAddressInput','focus',emptyField);
YAHOO.util.Event.addListener('emailAddressInput','blur',blurField);
YAHOO.util.Event.addListener('emailMarketingForm','submit',checkEmailForm);

function emptyField() {
    if (this.value == "type your email address here for updates") { this.value = "" };
}
function blurField() {
	if (this.value == "") { this.value = "type your email address here for updates" };
}
function checkEmailForm(e) {
    if (this.emailAddressInput.value == "type your email address here for updates") { alert("Please type in your email address"); this.emailAddressInput.focus(); YAHOO.util.Event.preventDefault(e) }
}