title: How to add optional command line parameter in bat file ( windows )
body: <p>I have a batch file in with the following parameter hard coded</p>
  
  <blockquote>
    <p>SET upgrade=false</p>
  </blockquote>
  
  <p>I want to give user an option to explicitly define the upload parameter. By default it should be false and if user explicitly define <code>upgrade=true</code> I should treat it as true. </p>
  
  <p>I also wants to check the validation for boolean value in upload parameter.</p>
  
  <p>I am new to batch file processing. I have tried with the default value processing.</p>
  
  <pre><code>if "%2"=="" goto false
  
  :false
  SET upgrade=false
  </code></pre>