var good;
function checkEmailAddress(field) {
// the following expression must be all on one line...
var goodEmail = field.value.match(/\b(^(\S+@).+((\.com)|(\.net)|(\.edu)|(\.mil)|(\.gov)|(\.org)|(\..{2,2}))$)\b/gi);
if (goodEmail){
good = true
} else {
alert('Digite um e-mail válido!')
field.focus()
field.select()
good = false
}
}

u = window.location;
m = "Gostaria de lhe recomendar um site!";
function mailThisUrl(){
good = false
checkEmailAddress(document.eMailer.address)
if (good){
// the following expression must be all on one line...
window.location = "mailto:"+document.eMailer.address.value+"?subject="+m+"&body="+document.title+" "+u;
}
}