title: Calculate Amount with Java Script by input value in text field
body: <p>I have created a php file where I need to calculate total amount by entering a value in a text field.</p>
  
  <p>My form code is like this:</p>
  
  <pre><code>&lt;input id='1' name='1' type='text' size='10' value='$visitors' /&gt;    
  &lt;input type='submit' name='submit' class='submit_button' value='Buy Visitors' /&gt;
  </code></pre>
  
  <p>Now what I want is, user will enter some value in text field lets say 15 so it should calculate with price like this </p>
  
  <pre><code>15 x 0.60 = 9
  </code></pre>
  
  <p>and answer should show after text field.</p>
  
  <p>Please help Me.</p>