====== < param > ======

===== Description =====

The <param> element specifies values that are passed into the <object> or in <subdialog>. When <param> is contained in a <subdialog> element, the values specified are used to initialize <var> declarations in the subdialog that is invoked.  The initialization takes precedence over the expr attribute in <var>.

===== Syntax =====

<code>
<param
name="String"
value="String"
expr="ECMAScript_Expression"
valuetype="data" | "ref"
type="MIME_type"/>
</code>

===== Attributes =====

|name|The name attribute is the name associated with the parameter. This attribute is required.|
|value|The value attribute is the string value of the parameter. This attribute is required and either value or expr is required.|
|expr|The expr attribute is an expression that yields the parameter value.  This attribute is required and either value or expr is required.|
|valuetype|The valuetype attribute indicates the reference type of the value.  This attribute is not used for <subdialog>.  This attribute is optional and defaults to data. \\ * data – the value is actual data. \\ * ref – the value referenced by a URI.|
|type|The type attribute is the media type of the result provided by a URI if the valuetype is ref.  This is only relevant for the uses of <param> in the <object> element.  This attribute is optional.|

===== Parents =====

<code>
<object>, <subdialog>
</code>

===== Children =====

<code>
None.
</code>

===== Extensions =====

<code>
None.
</code>

===== Limitations/Restrictions =====

<code>
None.
</code>

===== Example Code =====

This represents a document that calls the subdialog:
<code>
<?xml version="1.0"?>
<vxml version="2.0" xmlns="http://www.w3.org/2001/vxml">
 <form>
  <subdialog name="result" src="subdialog.vxml">
   <param name="birthday" expr="'2000-02-10'"/>
   <param name="age" value="100"/>
   <filled>
    <submit next="process.vxml"/>
   </filled>
  </subdialog>
 </form>
</vxml>
</code>

This represents a document containing the subdialog:
<code>
<?xml version="1.0"?>
<?xml version="1.0"?>
<vxml version="2.0" xmlns="http://www.w3.org/2001/vxml">
 <form id="getdriverslicense">
  <var name="birthday"/>
  <var name="age"/>
  <block>
   <prompt>
    Hello, your birthday is <value expr="birthday"/>
    and you are <value expr="age"/> years old.
   </prompt>
   <return/>
   </block>
 </form>
</vxml>
</code>