====== < catch > ======

===== Description =====
The <catch> element catches events thrown from the VoiceXML application or the platform.  The <catch> element associates a catch with a document, dialog or form item and contains executable content.  The <catch> element catches an event with the name that either matches exactly with the event attribute or a prefix match.  A prefix match means the event attribute is a token prefix of the thrown event, where the dot is the token separator. For example, <catch event="telephone.disconnect"> is a prefix match for event telephone.disconnect.transfer.  Please refer to Event Handling for the list of events and errors.

===== Syntax =====
<code>
<catch
event="event1 event2 ..."
count="Integer"
cond="ECMAScript_Expression">
child elements
</catch>
</code>

===== Attributes =====
|event|This attribute indicates the event or events to catch.  A space-separated list of events may be specified to catch multiple events.  The empty string matches all events.  This attribute is required.|
|count|The count attribute allows you to handle different occurrences of the same event differently.  Each <form>, <menu> and form item maintains a counter for each event that occurs while it is being visited.  These counters are reset each time the <form> or <menu> is re-entered.  When there is more than one <catch> element catching the same event, it will visit the element with a smallest count that is greater or equal to the current counter.  This attribute is optional.|
|cond|The cond attribute is a Boolean condition that must evaluate to true in order for the <catch> element to catch the event.  This attribute is optional.|

===== Anonymous Variables =====
There are two anonymous variables that are available within the scope of the <catch> element:
  * _event - the variable that contains the name of the event that was thrown.
  * _message - the variable that contains the message string from the corresponding <throw> element, or a platform-defined value for events raised by the platform.

===== Parents =====
<code>
<field>, <form>, <initial>, <menu>, <object>, <record>, <subdialog>, <transfer>, <vxml>
</code>

===== Children =====
<code>
<assign>, <audio>, <clear>, <disconnect>, <enumerate>, <exit>, <goto>, <if>, <prompt>, <reprompt>, <return>, <script>, <submit>, <throw>, <value>, <var>
</code>

===== Extensions =====
<code>
None.
</code>

===== Limitations/Restrictions =====
<code>
None.
</code>

===== Example Code =====
<code>
<?xml version="1.0"?>
<vxml version="2.0" xmlns="http://www.w3.org/2001/vxml">
 <form>
  <grammar> goodbye </grammar>
  <catch event="goodbye">
   Thanks for using this script, goodbye.
   <disconnect/>
  </catch>
  <field name="password">
    <prompt> what is the code word </prompt>
    <grammar> apple </grammar>
    <help> It is the name of a fruit </help>
    <catch event="noinput"> I did not hear you. </catch>
    <catch event="nomatch" count="1"> Noop. Try again </catch>
    <catch event="nomatch" count="2"> Noop. give another try </catch>
    <catch event="nomatch" count="3">
     Sorry. You didn't get it for three times. Bye
     <disconnect/>
    </catch>
   <filled>
    <if cond="password=='goodbye'">
     <throw event="goodbye"/>
    <else/>
     This is correct.
    </if>
   </filled>
  </field>
 </form>
</vxml>
</code>