<?xml version="1.0" encoding="UTF-8"?>
<vxml version="2.0" xmlns="http://www.w3.org/2001/vxml">

<meta name="description" content="DTMF grammar and script example"/>
<meta name="author" content="OptimSys, s.r.o., Czech Republic (http://www.optimsys.cz)"/>
<meta name="copyright" content="free for any purpose"/>

<script> <![CDATA[
  function isInteger (num) {
    return (num - Math.floor(num) == 0);
  }

  function prime(num) {
    if (num < 2) return 1;

    if (isInteger (num / 2)) return 2;

    var t = eval (Math.floor(Math.sqrt(num)));
    for (var i = 1; i <= t/2; i++) {
      var p = 2*i + 1;
      if (isInteger (num/p)) return p;
    }
    return 0;
  }
]]></script>

<form id="form">
  <field name="number">
    <nomatch>
      Please use your telephone keyboard. If you use any of the
      standard OptimTalk input components, the telephone keyboard
      can be simulated by function keys F1 to F12.
      <reprompt/>
    </nomatch>
    <nomatch count="2">
      Please use your telephone keyboard to enter a positive whole
      number.
    </nomatch>
    <nomatch count="3">
      Please learn what numbers mean first. I am giving up. Bye.
      <exit/>
    </nomatch>

    <prompt>
      Use your telephone keyboard and type a positive whole number
      with maximum ten digits. Finish the typing with #. Then I'll
      tell you if it is a prime number. The telephone keyboard
      can be simulated by function keys F1 to F12.
    </prompt>

    <grammar root="main" mode="dtmf">
      <rule id="main" scope="public">
        <tag>out = 0;</tag>
        <item repeat="1-10">
          <ruleref uri="#num"/>
           <tag> out = out * 10 + parseInt(rules.num) </tag>
        </item>
      </rule>
      <rule id="num">
        <one-of>
          <item>1</item>
          <item>2</item>
          <item>3</item>
          <item>4</item>
          <item>5</item>
          <item>6</item>
          <item>7</item>
          <item>8</item>
          <item>9</item>
          <item>0</item>
        </one-of>
      </rule>
    </grammar>

    <filled>
      <var name="divisor" expr="prime(number)"/>
      <if cond="divisor == 0">
        <prompt>
          <value expr="number"/> is a prime number.
        </prompt>
      <elseif cond="divisor == 1"/>
        <prompt>
          <value expr="number"/> is not a prime number by definition.
        </prompt>
      <else/>
        <prompt>
          <value expr="number"/> is not a prime number, it can be divided by
          <value expr="divisor"/>.
        </prompt>
      </if>
    </filled>
  </field>
</form>

</vxml>