title: php credit card validation
body: <p>I'm new to php and reading a couple of php books as well as going over some tutorials. 
  I cant seem to get this php validation project to work write. Its seem not to get rid of any spaces or dashes. not sure what I'm doing wrong. </p>
  
  <pre><code>&lt;html&gt;
   &lt;body&gt;
    &lt;h1&gt;Validate Credit Card&lt;/h1&gt;&lt;hr /&gt;
  
  &lt;form action="ValidateCreditCard.php" method="get" encytype="application/x-www-form -urlencoded"&gt;
   &lt;p&gt;&lt;input type="text" name="ccnumber" size="20" value="&lt;?php if(!empty($_GET['ccnumber']))     echo $_GET['ccnumber'] ?&gt;" /&gt;&lt;/p&gt;   
    &lt;p&gt;&lt;input type="submit" value="Validate Credit Card" /&gt;
  &lt;/form&gt;&lt;hr /&gt;
     &lt;?php
        if (!isset($_GET['ccnumber']))
      echo "&lt;p&gt;Enter your credit card number.&lt;/p&gt;";
      else{
      $Payment = $_GET['ccnumber'];
      $ValidPayment = str_replace("_", "", $Payment);
      $ValidPayment = str_replace("_", "", $ValidPayment);
      if (!is_numberic($ValidPayment))
          echo "&lt;p&gt;You did not enter a valid credit card number!&lt;/p&gt;";
          else
           echo "&lt;p&gt;Your credit card number is $ValidPayment.&lt;/p&gt;";
      }   
  ?&gt;
  
   &lt;/body&gt;    
  &lt;/html&gt;
  </code></pre>