error dialer golang gorilla websocket #2

package main

import (
    "fmt"
    "github.com/gorilla/websocket"
    "log"
    "io/ioutil"
    "net/url"
)

var origin = "http://localhost:8088/"
var urlAsterisk = "ws://localhost:8088/ari/events?api_key=asterisk:asterisk&app=hello-world"

func sendString(b string) {
    fmt.Println(b)
}

func readLoop(c *websocket.Conn) {
    for {
        _, r, err := c.NextReader()
        if err != nil {
            c.Close()
            break
        }
        if b, err := ioutil.ReadAll(r); err == nil {
            go sendString(string(b))
        }
    }
}

func main() {
    u, err := url.Parse(urlAsterisk)
    if err != nil {
        return
    }
    DialerWS := new(websocket.Dialer)
    fmt.Println(DialerWS)
    fmt.Println("toto1")
    DialerWS.NetDial("tcp", u.Host)
    fmt.Println("toto2")
    for {
        wsConn, _, err := DialerWS.Dial(urlAsterisk, nil)
        fmt.Println("toto")
        if err != nil {
            log.Fatal(err)
        }
        readLoop(wsConn)
    }
}