# Validating a VoiceXML file

The VoiceXML editor provides a way to check whether the structure of the document is well-formed and validates the document against the supplied Document Type Definition (DTD).

As you edit a VoiceXML file, a set of constraints is placed on that file through the DTD. In this mode, the content of an element must be valid to use the guided editing options of the XML editor.

The editor automatically checks the validity of the document during a save operation. Other validation of VoiceXML documents can occur when adding elements though the Outline or Design View. Errors are listed in the Problems view. To clear the list, correct the errors and save the .vxml file.

Note: The DOCTYPE declaration is necessary to enable proper validation and Content Assist. If one is not present, the document will not validate.

For troubleshooting information, see Troubleshooting a VoiceXML file.

Related Information
What is VoiceXML?
VoiceXML coding tips
Creating a VoiceXML file