Untitled

Error: 500

Internal Servlet Error:
java.lang.NoClassDefFoundError: com/mysql/jdbc/Driver
    at QueryConst.connect(QueryConst.java:23)
    at QueryConst.doPost(QueryConst.java:38)
    at javax.servlet.http.HttpServlet.service(HttpServlet.java:747)
    at javax.servlet.http.HttpServlet.service(HttpServlet.java:840)
    at com.sun.web.core.ServletWrapper.handleRequest(ServletWrapper.java:155)
    at com.sun.web.core.InvokerServlet.service(InvokerServlet.java:168)
    at javax.servlet.http.HttpServlet.service(HttpServlet.java:840)
    at com.sun.web.core.ServletWrapper.handleRequest(ServletWrapper.java:155)
    at com.sun.web.core.Context.handleRequest(Context.java:414)
    at com.sun.web.server.ConnectionHandler.run(ConnectionHandler.java:139)
Caused by: java.lang.ClassNotFoundException: com.mysql.jdbc.Driver
    at java.net.URLClassLoader.findClass(Unknown Source)
    at java.lang.ClassLoader.loadClass(Unknown Source)
    at sun.misc.Launcher$AppClassLoader.loadClass(Unknown Source)
    at java.lang.ClassLoader.loadClass(Unknown Source)
    ... 10 more

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

public class QueryConst extends HttpServlet {

    static Connection link;
    static String myURL = "jdbc:mysql:";
    static final private String CONTENT_TYPE = "text/html";
    /*  *************************** */
    /*  CONNECTING TO THE DATA BASE */
    /*  *************************** */

    public static void connect() {
        try {
            DriverManager.registerDriver(new com.mysql.jdbc.Driver());
            link = DriverManager.getConnection(myURL+"//localhost/airliner?user=root+&password=");
        } catch (SQLException e) {
            System.out.println("Connection failure: " + e.getMessage());
        }
    }

    /*  ******************************* */
    /*  CATCHING THE HTTP POST REQUEST  */
    /*  ******************************* */

    public void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
        Statement question;
        String query;
        ResultSet answer;
        connect();
        response.setContentType(CONTENT_TYPE);
        PrintWriter out = response.getWriter();
        out.println("<html>");
        out.println("<head><title>SQL request</title></head>");
        out.println("<body>");
        out.println("<form method="post" action="http://localhost:8080/servlet/queryConst">");
        out.println("SELECT");
        out.println("<select name="champs" id="champsTable"></select>");
        out.println("FROM");
        out.println("<select name="table" id="choixTable"></select>");
        out.println("WHERE");
        out.println("<select name="condition1" id="condition1"></select>");
        out.println("<select name="operateur" id="operateur">"
                + "<option value="<"><</option>"
                + "<option value=">">></option>"
                + "<option value="=">=</option>"
                + "<option value="<="><=</option>"
                + "<option value=">=">>=</option>"
                + "</select>");
        out.println("<select name="condition2" id="condition2"></select>");
        out.println("<input type="submit" value="Go"></p>");
        out.println("</form>");

        out.println("</body></html>");

    }

    /*  ******************************* */
    /*  CATCHING THE HTTP GET REQUEST   */
    /*  ******************************* */

    public void doGet(HttpServletRequest requete, HttpServletResponse reponse) throws ServletException, IOException {
        doPost(requete,reponse);
    }

    /*  ******************* */
    /*  SERVLET DESTRUCTOR  */
    /*  ******************* */

    public void destroy() {
        super.destroy();
        try { link.close();
        } catch (Exception e) {
            System.err.println(e.getMessage());
        }
    }
}