title: How to detect the windows OS in ANT
body: <p>I'm using ant to compile a Java application.  The problem is some of the devs are on win 7 and others are on xp and vista.  Part of the compiling is to build an msi using WIX, on win7 this is one directory and on xp and vista it's in another.</p>
  
  <p>The ant task is controlled in Maven. I'm after a way of telling the difference between windows os's in ant with a conditional tag to set the wix directory. Any ideas?</p>
  
  <p>I know it will be in this format:</p>
  
  <pre><code>&lt;if&gt;
     &lt;condition property="isWin7"&gt;
      Check for windows 7
     &lt;/condition&gt;
     &lt;then&gt;
      set wix path to win 7 installation
     &lt;/then&gt;
     &lt;else&gt;
      set to vista/xp wix installation
     &lt;/else&gt;
   &lt;/if&gt;
  </code></pre>
  
  <p>Any help would be great.</p>