谁能帮我找下这段JSP连接数据库的错误？

String sql ="insert into user_info values('"+username+"','"+nicheng+"','"+password+"','"+email+"')";
                    int ret = 0;
                    ret = statement.executeUpdate(sql);
                    if(ret!=0){
                    out.println("<script language=\"javascript\">alert(\"用户注册成功！\");window.location.href=\"index.jsp\";</script>");
                    connection.close();
                    statement.close();
                    rs.close();
                    }else{
                    out.println("<script language=\"javascript\">alert(\"注册失败\");window.lacation.href=\"zhuce.jsp\";</script>");
                    connection.close();
                    statement.close();
                    rs.close();

总是显示我这段代码有错误，但是我也不知道错在哪里啊。。。。。。。上面的连接绝对没有问题。就错在这段代码了。。。。。。