Android : Android AsyncTask Getting Data From Mysql Error

I have a mysql database and want to get information from it with android.I can print how many records it has but when try to print datas it gives FATAL EXCEPTION:AsyncTask #1 error and also it gives;

java.lang.RuntimeException: An error occurred while executing doInBackground()

Codes;

 try{    jArray = new JSONArray(result);
      JSONObject json_data=null;


  //m=jArray.length();

      for(int i=0;i<jArray.length();i++){
             json_data = jArray.getJSONObject(i);
            name=json_data.getString("name");

                  }} 

How can i fix this problem?

Thanks...