ASP .net xml search

This is a search engine kind of project where the documents to be searched are XML docs. I already have the project with me which is halfway done using ASP .NET. What it does is, when the user enters a keyword, it is searched in an XML doc and the returns the result. Lets say if the XML doc is a movie database of the format skyfallDaniel.... If the search keyword is Skyfall, it will return skyfallDaniel...'. The problem is, it is being searched in only 1 xml doc. Instead i would like the search to be performed over several xml docs and return the results in the ranked order. I will upload my files if anyone is interested in extending the project. I want this task to be done within 1 week.