make voiceXML to read the result returned by the server

I am new in voiceXML and I am wondering how to read a value return by the server after post. I want voiceXML to read the server's response. According to voiceXML documentation, I understand that the result should be in XML.

Here is my node.js/express.js code that receives the result:

app.post("/getData", function (req, res) {
    console.log(JSON.stringify(req.body));
    res.header('Content-Type','text/xml').send('<?xml version="1.0" ?> <vxml version="2.0"> <block> <prompt> The time in Milwaukee is 10 </prompt> </block> </vxml>');
});

Here is the screenshot showing that I am successfully receiving the posted content:

Here is the screenshot showing that I am successfully sending the XML result:

Here is my voiceXML file:

<?xml version="1.0" encoding="UTF-8"?>
<!DOCTYPE vxml PUBLIC "-//BeVocal Inc//VoiceXML 2.0//EN" "http://cafe.bevocal.com/libraries/dtd/vxml2-0-bevocal.dtd">
<vxml xmlns="http://www.w3.org/2001/vxml" xmlns:bevocal="http://www.bevocal.com/" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" version="2.0">
    <form scope="dialog">
        <field name="name" modal="false">
            <grammar src="grammars.grammar#Names"/>
            <prompt>Whats your name?</prompt>
            <filled>
                <prompt>Hello <value expr="name"/>
                </prompt>
            </filled>
        </field>

        <field name="city" modal="false">
            <grammar src="grammars.grammar#Cities"/>
            <prompt>What city are you from?</prompt>
            <filled>
                <prompt>You are from <value expr="city"/>
                </prompt>
            </filled>
        </field>

        <field name="country" modal="false">
            <grammar src="grammars.grammar#Countries"/>
            <prompt>What country are you from?</prompt>
            <filled>
                <prompt>You are from <value expr="country"/>
                </prompt>
            </filled>
        </field>

        <field name="cityTime">
            <prompt>
                What city would you like the time for?
            </prompt>
            <grammar type="application/x-nuance-gsl">
                [denver (san francisco) ]
            </grammar>
        </field>
        <field name="formatTime">
            <prompt>
                Twelve hour or twenty four hour clock?
            </prompt>
            <grammar type="application/x-nuance-gsl">
                [[twelve (twenty four)] ?hour]
            </grammar>
        </field>
        <block>
            <submit next="http://65.29.170.122/getData" method="post" namelist="name city country cityTime formatTime" />
        </block>
    </form>
</vxml>

Two approaches are available: First, after collecting your input submit the form and the response should be a new VoiceXML document that plays your data.

Second, if your browser supports it (most do), you can use the Data element to make a request from within the VoiceXML form. The response needs to be XML. VoiceXML provides a way to walk the resulting DOM to get your data.

As for speaking the data, most browsers support the say-as element of SSML within a prompt. For most professional applications, the typically approach is to build a javascript library to assemble and play a set of recordings to play the time.