Forms

A form in a VoiceXML document presents information and gathers input from the user. A form is represented by the <form> tag and has an ID attribute associated with it. The ID attribute is the name of the form.
Following is an example of a form element:

<form id="hello">
  <block>
  Hello world!
  </block>
</form>

In this example, the name of the form is “hello” and “Hello world!” is presented to the user.

** Form Items **

There are two types of form items, field items and control items. A field item prompts the user on what to say or key in, and then collects that information and fills in the field item variable. A field item also has grammars that define the allowed inputs, event handlers to process the resulting events, and a <filled> element that defines an action to be taken after the field item variable has been filled.

Following is a list of the types of field items:

< field >	The < field > form is the value of the field item obtained from the user via speech or DTMF.
< record >	The < record > form is the value of the field item which is an audio clip recorded by the user, such as a voice mail message, which can be collected by the <record> element.
< transfer >	The < transfer > form is used for transferring the user to another telephone number.
< object >	The < object > form invokes platform-specific objects with one or more properties.
< subdialog >	Like a function call, the form invokes a call to another dialog on the current page or another VoiceXML document. The task of a control item is to help control the gathering of the form's fields.

Following are two types of control items:

< block >	The < block > control is a sequence of statements used for prompting and computation.
< initial >	The < initial > control is useful in mixed initiative dialogs that prompt the user for information.

** Variables and Conditions **

A form item variable is associated with each form. The form item 'variable by default' is initially set to 'undefined' and contains a result (collected from the user) once a form item has been interpreted. You can define the name of a form item variable by using the name attribute. A guard condition exists for each form item. The guard condition tests whether the item's variable currently has a value. If a value exists, then the form item is skipped.