title: passing argument using add_action in wordpress!
body: <p>I have a very strange problem in my wordpress development,</p>
  
  <p>in fucntions.php I have the following code</p>
  
  <pre><code>//mytheme/functions.php
  $arg = "HELP ME";
  add_action('admin_menu', 'my_function', 10, 1);
  do_action('admin_menu',$arg );
  
  function my_function($arg)
  {   
      echo "the var is:".$arg."&lt;br&gt;";
  }
  </code></pre>
  
  <p>the output is </p>
  
  <pre><code>the var is:HELP ME
  the var is:
  </code></pre>
  
  <p>Why the function repeated 2 times? Why has the argument "help me" been passed correctly and the 2nd time it havent been passed?</p>
  
  <p>I have been trying all my best for 2 days and searched in many places to find a solution but I had no luck.</p>
  
  <p>What I am trying to do is simple! I just want to pass argument to a function using add_action?</p>