title: how to run a r program written in a file with .r extention?
body: <p>I have a file that have some R program code i.e. <code>progm.r</code>, kept it on my desktop: <code>C:\Users\sandeeptiw\Desktop\progm.r</code>.</p>
  
  <p>I have set the variable path like: <code>C:\Program Files\R\R-3.1.1\bin\</code></p>
  
  <p>Now, how can I run this program ?  </p>