c# string script to javascirpt?

Ok kind of a n00b question; I am converting a c# script to a javascript but I can not figure out how the following c# script should be written in javascript (inside a function). (this is the piece of the script that goes wrong, the “string filepath” is properbly the problem… what should it be if written in javascript?)

    function WriteToXml()
  string filepath = Application.dataPath + @"/XML/test.xml";

var filepath : String = Application.dataPath + “/XML/test.xml”;