<html>
<head>
<title>online exam</title>
</head>
<body>
<div align="center">
<form method="post" action="Tab">
<p>4.what is currency of USA?</p>
<input type="radio" name="d" onclick="getAnswer('a')" value="a "/>dollar
<input type="radio" name="d" onclick="getAnswer('b')" value="b "/>pound
<input type="radio" name="d" onclick="getAnswer('c')" value="c "/>rupees
<input type="radio" name="d" onclick="getAnswer('d')" value="d "/>yen<br />
</form>
</div>
</body>
</html>
package src;
import java.io.*;
import java.net.*;
import java.sql.*;
import javax.servlet.*;
import javax.servlet.http.*;
public class Tab extends HttpServlet {
protected void processRequest(HttpServletRequest request, HttpServletResponse response throws ServletException, IOException {
response.setContentType("text/html;charset=UTF-8");
PrintWriter out = response.getWriter();
int count=0,wrng=0;
String radio0=request.getParameter("a");
out.println(radio0);
if("c".equals(radio0))
count++;
else
wrng++;
out.println("<html><head><title>result</title></head><body>" +
"<div align=\"center\"><h1><u>Result</u></h1><p>correct answers are:</p>"+count+"<br/><p>wrong answers are :</p>"+wrng+"</div></body></html>");
out.close();
}
protected void doGet(HttpServletRequest request, HttpServletResponse response)
throws ServletException, IOException {
processRequest(request, response);
}
protected void doPost(HttpServletRequest request, HttpServletResponse response)
throws ServletException, IOException {
processRequest(request, response);
}
public String getServletInfo() {
return "Short description";
}
}
//Here the radio0 returns null value.pls advice me