In this paper we present a proposal for the development of dialog systems that, on the one hand, takes into account the benefits of using standards like VoiceXML, whilst on the other, includes a statistical dialog module to avoid the effort of manually defining the dialog strategy. This module is trained using a labeled dialog corpus, and selects the next system response considering a classification process that takes into account the dialog history. Thus, system developers only need to define a set of VoiceXML files, each including a system prompt and the associated grammar to recognize the users responses to the prompt. We have applied this technique to develop a dialog system in VoiceXML that provides railway information in Spanish.