Check if parameter exists in servlet request

<%@page language="java" session="true" contentType="text/html;charset=ISO-8859-1" %> 

<form name="frm" method="get" action="../user/GetParameter">
<b><font color="blue">You can select parametrs here to send request to servlet.
       </font></b>
    <table>
	<tr><td>Parameter1</td><td><input type="checkbox" name="Parameter1" value="1">
         </td></tr>
	<tr><td>Parameter2</td><td><input type="checkbox" name="Parameter2" value="2">
              </td></tr>
	<tr><td>Parameter3</td><td><input type="checkbox" name="Parameter3" value="3">
              </td></tr>
	<tr><td>Parameter4</td><td><input type="checkbox" name="Parameter4" value="4">
              </td></tr>
       <tr><td></td>
            <td><input type="submit" name="submit" value="submit"/></td>
        </tr>
    </table>
</form>

import java.io.*;
import java.util.*;
import javax.servlet.*;
import javax.servlet.http.*;

public class GetParameter extends HttpServlet {
  public void doGet(HttpServletRequest request,HttpServletResponse response)
    throws IOException, ServletException{
    response.setContentType("text/html");
    PrintWriter out = response.getWriter();    
    Enumeration parameter = request.getParameterNames();
    int count = 0;
	// check that parameter is exist or not
    while(parameter.hasMoreElements()){
		parameter.nextElement();
		count++;
	}
	if(count==1){
	  out.println("<font color=\"red\" size=\"+1\">
          No parameter in servlet request.<font><br>");	
	}
	else {    
         out.println("<b><font color='blue'>You have send "+ (count-1) +
			 " parameters in servlet are.</font></b>");
	}
  }
}

<servlet>
    <servlet-name>GetParameter</servlet-name>
    <servlet-class>GetParameter</servlet-class>
</servlet> 
<servlet-mapping>
    <servlet-name>GetParameter</servlet-name>
    <url-pattern>/GetParameter</url-pattern>
</servlet-mapping>