title: Regex to allow only a single dot in a textbox
body: <p>I have one text input.</p>
  
  <p>I wrote a regex for masking all special characters except <code>.</code> and <code>-</code>. Now if by mistake the user enters two <code>.</code> (dots) in input, then with the current regex</p>
  
  <pre><code>var valueTest='225..36'
  
  valueTest.match(/[^-.\d]/)
  </code></pre>
  
  <p>I expected that the number will not pass this condition</p>
  
  <p>How to handle this case. I just want <em>one</em> <code>.</code> (dot) in input field since it is a number.</p>