title: HTTP Status 500 - null
body: <p>I wrote a java servlet program but when i run it, It was showing the Error HTTP Status 500 - null What it means ;
  My source code is on <a href="https://stackoverflow.com/questions/13904103/java-lang-classnotfoundexception-oracle-jdbc-driver-oracledriver#comment19161338_13904103"><strong>this page</strong></a>.</p>
  
  <p>The error was </p>
  
  <pre><code>HTTP Status 500 - null
  type Exception report
  message null
  description The server encountered an internal error that prevented it from fulfilling this request.
  exception
   java.lang.NumberFormatException: null
  java.lang.Integer.parseInt(Unknown Source)
  java.lang.Integer.parseInt(Unknown Source)
  skypark.Registration.doPost(Registration.java:56)
  javax.servlet.http.HttpServlet.service(HttpServlet.java:647)
  javax.servlet.http.HttpServlet.service(HttpServlet.java:728)
  </code></pre>
  
  <p>Please help me to resolve this....</p>