title: Check if URL has letters and symbols on selected link
body: <p>i want deny the letters and symbols Of the current page and selected url</p>
  
  <p>i only want numbers</p>
  
  <pre><code>if(@$_GET['page'] == '$string') {
  
  if (preg_match('/[\'^£$%&amp;*()}{@#~?&gt;&lt;&gt;,|=_+¬-]/', $string))
  {
  
  die("error : page url found letters and symbols");
  }
  }
  </code></pre>
  
  <p>for example xxx.com/index.php?page=  &lt;---- i only want numbers </p>
  
  <p>because some people put letters and symbols
  like this
  xxx.com/index.php?page=ABCD
  xxx.com/index.php?page=!@#$</p>
  
  <p>i dont want this happen because i want protect my website from sql injection</p>
  
  <p>how to deny letters and symbols from selected url :index.php?page=
  ؟</p>