Simple jQuery validation script works but it uses a ton of if/else statements
I would recommend that you use the JQuery validation plugin (http://docs.jquery.com/Plugins/Validation) then your validation declaration would be as follows (fields which do not exist are ignored):

$("#footer_newsletter").validate(
    rules: {
            email: {
                    required: true,
                    email: true
                   },
            country: "required",
            gender: "required" 
    },
    messages: {
             email: {
                     required: "Please enter an email",
                     email: "Please enter a valid email address"
                    },
             country: "Please select a country",
             gender: "Please select your gender"
    }
);