title: Typescript - module functions reference in different file - "could not find symbol"
body: <p>Apologies if the answer to this is simple, or I've mis-read the typescript documentation, but..</p>
  
  <p>I have a module:</p>
  
  <pre><code>module Utils{
  
      export function MyFunction(str: string):string {
          return // something to do with string
      }
  
  }
  </code></pre>
  
  <p>I want to use this in another .ts file (Clients.ts) so at the top I add a reference and try to use it:</p>
  
  <pre><code>/// &lt;reference path="Utils.ts" /&gt;
  Utils.MyFunction(str);
  </code></pre>
  
  <p>But get the following error:</p>
  
  <pre><code>/*
  
  Compile Error. 
  See error list for details
   [path]/Clients.ts(26,39): error TS2095: Could not find symbol 'Utils'.
   [path]/Clients.ts(30,49): error TS2095: Could not find symbol 'Utils'.
  error TS5037: Cannot compile external modules unless the '--module' flag is provided.
  
  
  */
  </code></pre>
  
  <p>Could anybody explain what I'm doing wrong?</p>
  
  <p>Using VS2012, with Web Essentials and TypeScript 0.9.1</p>
  
  <p>Thanks.</p>