Android : HTTP return nothing in android

I am new in android and i try to get values from mysql from my own server. I write the following code everything is correct but when I debug http response null and execution skip the another code and got exception area.

Plz help me urgent

HttpClient httpclient = new DefaultHttpClient();
    HttpPost httppost = new HttpPost("http://mysitename.com/getdata.php");
try
        {
             httppost.setEntity(new UrlEncodedFormEntity(nameValuePairs));
            **HttpResponse response = httpclient.execute(httppost);** 
            HttpEntity entity = response.getEntity();
            is = entity.getContent();
            Log.e("pass 1", "connection success ");
    }
        **catch(Exception e)**
    {
            Log.e("Fail 1", e.toString());
            Toast.makeText(getApplicationContext(), "Invalid IP Address",
            Toast.LENGTH_LONG).show();
    }