title: Calling a PHP function by onclick event
body: <p>I am trying to call a function by &quot;onclick&quot; event of the button.
  When I do that it shows error message.
  Can anybody help me out on this so that when I click on the button it should call the function and execute it.</p>
  <p><strong>My PHP code is:</strong></p>
  <pre><code>&lt;?php
      function hello() {
          echo &quot;Hello&quot;;
      }
      echo &quot;&lt;input type='button' name='Release' onclick= hello(); value='Click to Release'&gt;&quot;;
  ?&gt;
  </code></pre>
  <p>What is wrong with this code?</p>