error occurred: Can not issue SELECT via executeUpdate()

[prajwalhegde]

package com;
 
import com.opensymphony.xwork2.ActionSupport;
import java.sql.*;
 
 
/**
 * <p> Validate a user login. </p>
 */
public  class retrieve  extends ActionSupport 
{
 
      public String execute() throws Exception 
      {          
          String url = "jdbc:mysql://localhost:3306/";
          String dbName = "login";
          String driverName = "com.mysql.jdbc.Driver";
          String userName = "root";
          String passWord = "12345";
          Connection con=null;
          Statement stmt=null;
          try{
          Class.forName(driverName).newInstance();
          con=DriverManager.getConnection(url+dbName, userName, passWord);
          stmt=con.createStatement();
          }
          catch(Exception e){
          System.out.println(e.getMessage());
          }
          String username=getUsername();
          String password=getPassword();
          stmt = con.createStatement();
          int val = stmt.executeQuery("SELECT USERNAME , password FROM employee WHERE username='admin' AND password ='admin' Values ('"+username+"','"+password+"')");
          if(val == 0)
          {
                  return ERROR;
          }
          else
          {
              return SUCCESS;
          }
      }
      // ---- Username property ----
 
      private String username;
      public String getUsername() 
      {
          return username;
      }
 
      private String password;
      public String getPassword()
      {
          return password;
      }
 
}

Above is my code .. please help me in debugging this ASAP