VS 2012中不提供发布配置

I have a web application in 2012, which I suppose converted from 2010 solution. It has only one configuration "Debug" listed in toolbar, configuration manager and publish wizard. Is there any settings to be changed in the web.config or other places? I don't think its a setting at visual studio level because other new projects has both the Debug and Release settingsI have a web application in 2012, which I suppo