It is a form item that calls another form to execute specific instructions and to collect data. They are useful as they allow programmers to use other documents without exiting the current document. The execution of the subdialog is complete when it encounters the return instruction. Attributes like namelist, method and enctype are used only when the specified document has a non-VoiceXML application. Fetchtimeout, fetchhint and caching are used only when the URL of src specified is in another document.



Name of the variable associated with this form item.


URI of the subdialog


An ECMAScript expression defining an initial value for this form item. If expr has a value other than undefined then this element will not be executed.


An ECMAScript expression which evaluates an expression containing the URI of the subdialog.


A boolean which must evaluate to true to visit this element.


When set true all other grammars will be inactive while the control is in this element.


A list of variables to submit through the http protocol.


Indicates the request mode and can be either get or post. If the variables specified by the “namelist” are passed to the server through ‘http get’ then it has the value get else post.


It is the MIME encoding type of the submitted document containing the subdialog


It can be either ‘fast’ or ‘safe’. When set to fast (default) a cached copy of the file will be used if already downloaded and still exists in the cache. When set to safe will download the file every time executing this element.


 Interval of time to wait for before throwing an “error.badfetch” event. It is platform dependent.


This can be either ‘safe’ or ‘prefetch’. Prefetch tells the interpreter to retrieve the file when the document is executed while safe indicates that the file can be downloaded only while executing this element.




PCDATA, audio, catch, enumerate, error, filled, help, noinput, nomatch, param, prompt, property, value