VoiceXML Reference

VoiceXML elements are the functional units of any VoiceXML program.  They are classified into different items namely form items, field items, input items and control items.

Variables: Variables declared in VoiceXML are similar to the ECMAScript/JavaScript with slight differences. Undefined, null, boolean, string, number and object are the 6 major types of variables. Variables cannot begin with “_” as variables beginning with this are used internally.

Scope of the variables: The scope of the variable depends on the place where they are declared. Variables can be declared in any of the following scopes:





Based on platform used and are available across a particular session.


Children of vxml of root document. Available to all documents specified in the root


Declared in vxml of the document. Available only to that document


Declared within the dialog (form/menu)


Declared within the form items like field, block catch.


The list on the left includes different VoiceXML elements supported by AsterUVX. Anyone can develop VoiceXML-based voice applications utilizing these elements.  Once you have created your application, test it for free on SoftSyl's AsterUVX platform.