function valida_comic(){
    var emailExp = new RegExp("^[0-9a-z\\._]+@[0-9a-z]+\\..+$","i");
    var email1 = document.comic.email1.value;
    var email2 = document.comic.email2.value;
    var email3 = document.comic.email3.value;
    var email4 = document.comic.email4.value;
	var nombre = document.comic.nombre.value;
    
    try {
        var email = document.comic.email.value;
    }
    catch (e) {
        var email = "not";
    }

	if (nombre == "" || nombre == "Nombre*"){
		alert("Por favor ingres\xE1 tu nombre");
		document.comic.nombre.focus();
		return 0;   
    }
    
	if (email != "not"){
       if (!emailExp.test(email)) {
        alert("Tu eMail no es correcto");
        document.comic.email.focus();
        return 0;
       }    
    }
	
    if(email1 == "eMail Amigo 1" && email2 == "eMail Amigo 2" && email3 == "eMail Amigo 3" && email4 == "eMail Amigo 4") {
        alert("Por favor ingres\xE1 el eMail de tu amigo.");
        document.comic.email1.focus();
        return 0;
    } else if (email1 != "eMail Amigo 1" && !emailExp(email1)) {
        alert("El eMail no es correcto");
        document.comic.email1.focus();
        return 0;
    } else if (email2 != "eMail Amigo 2" && !emailExp(email2)) {
        alert("El eMail no es correcto");
        document.comic.email2.focus();
        return 0;
    } else if (email3 != "eMail Amigo 3" && !emailExp(email3)) {
        alert("El eMail no es correcto");
        document.comic.email3.focus();
        return 0;
    } else if (email4 != "eMail Amigo 4" && !emailExp(email4)) {
        alert("El eMail no es correcto");
        document.comic.email4.focus();
        return 0;
    }
    
    document.comic.submit();
}