java.lang.String cannot be converted to JSONObject

Below is my code for accessing the database and I am getting the following error:

org.json.JSONException: Value

       public void onClick(View v) {
            // TODO Auto-generated method stub

            tim = time.getText().toString();
            na = name.getText().toString();
            da = date.getText().toString();

            insert();
        }
    });
}}

public void insert()
{
    ArrayList<NameValuePair> nameValuePairs = new ArrayList<NameValuePair>();

    nameValuePairs.add(new BasicNameValuePair("time",tim));
    nameValuePairs.add(new BasicNameValuePair("name",na));
    nameValuePairs.add(new BasicNameValuePair("date",da));

    try
    {
        HttpClient httpclient = new DefaultHttpClient();
        HttpPost httppost = new HttpPost("http://10.0.2.2/mts.php");
        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();
    }

    try
    {
        BufferedReader reader = new BufferedReader
                (new InputStreamReader(is,"iso-8859-1"),8);
        StringBuilder sb = new StringBuilder();
        while ((line = reader.readLine()) != null)
        {
            sb.append(line + "\n");
        }
        is.close();
        result = sb.toString();
        Log.e("pass 2", "connection success ");
    }
    catch(Exception e)
    {
        Log.e("Fail 2", e.toString());
    }

    try
    {
        JSONObject json_data = new JSONObject(result);
        code=(json_data.getInt("code"));

        if(code==1)
        {
            Toast.makeText(getBaseContext(), "Inserted Successfully",
                    Toast.LENGTH_SHORT).show();
        }
        else
        {
            Toast.makeText(getBaseContext(), "Sorry, Try Again",
                    Toast.LENGTH_LONG).show();
        }
    }
    catch(Exception e)
    {
        Log.e("Fail 3", e.toString());
    }
}

This the php code Errors are:

Deprecated: mysql_connect(): The mysql extension is deprecated and will be removed in the future: use mysqli or PDO

and

Warning: mysql_connect() line 7

<?php
    $host='127.0.0.1';
    $uname='root';
    $pwd='password';
    $db="android";

enter code here

$con = MySQLi($host,$uname,$pwd) or die("connection failed");
    mysql_select_db($db,$con) or die("db selection failed");

    $id=$_REQUEST['time'];
    $name=$_REQUEST['name'];
    $date=$_REQUEST['date'];

    $flag['code']=0;

    if($r=mysql_query("insert into sample values('$time','$name',$'date') ",$con))
    {
        $flag['code']=1;
        echo"";
    }

    print(json_encode($flag));
    mysql_close($con);
?>

logcat

548-548/com.example.gurucharan.mts D/dalvikvm﹕ Not late-enabling CheckJNI (already on)
548-548/com.example.gurucharan.mts D/dalvikvm﹕ GC_FOR_ALLOC freed 123K, 3% free 9218K/9415K, paused 60ms
548-548/com.example.gurucharan.mts I/dalvikvm-heap﹕ Grow heap (frag case) to 12.827MB for 3940072-byte allocation
548-554/com.example.gurucharan.mts I/dalvikvm﹕ threadid=3: reacting to signal 3
548-551/com.example.gurucharan.mts D/dalvikvm﹕ GC_CONCURRENT freed 1K, 2% free 13065K/13319K, paused 5ms+16ms
548-554/com.example.gurucharan.mts I/dalvikvm﹕ Wrote stack traces to '/data/anr/traces.txt'
548-554/com.example.gurucharan.mts I/dalvikvm﹕ threadid=3: reacting to signal 3
548-554/com.example.gurucharan.mts I/dalvikvm﹕ Wrote stack traces to '/data/anr/traces.txt'
548-554/com.example.gurucharan.mts I/dalvikvm﹕ threadid=3: reacting to signal 3
548-554/com.example.gurucharan.mts I/dalvikvm﹕ Wrote stack traces to '/data/anr/traces.txt'
548-554/com.example.gurucharan.mts I/dalvikvm﹕ threadid=3: reacting to signal 3
548-554/com.example.gurucharan.mts I/dalvikvm﹕ Wrote stack traces to '/data/anr/traces.txt'
548-548/com.example.gurucharan.mts D/libEGL﹕ loaded /system/lib/egl/libGLES_android.so
548-548/com.example.gurucharan.mts D/libEGL﹕ loaded /system/lib/egl/libEGL_emulation.so
548-548/com.example.gurucharan.mts D/﹕ HostConnection::get() New Host Connection established 0xd77e8, tid 548
548-548/com.example.gurucharan.mts D/libEGL﹕ loaded /system/lib/egl/libGLESv1_CM_emulation.so
548-548/com.example.gurucharan.mts D/libEGL﹕ loaded /system/lib/egl/libGLESv2_emulation.so
548-554/com.example.gurucharan.mts I/dalvikvm﹕ threadid=3: reacting to signal 3
548-554/com.example.gurucharan.mts I/dalvikvm﹕ Wrote stack traces to '/data/anr/traces.txt'
548-548/com.example.gurucharan.mts W/EGL_emulation﹕ eglSurfaceAttrib not implemented
548-548/com.example.gurucharan.mts D/OpenGLRenderer﹕ Enabling debug mode 0
548-554/com.example.gurucharan.mts I/dalvikvm﹕ threadid=3: reacting to signal 3
548-554/com.example.gurucharan.mts I/dalvikvm﹕ Wrote stack traces to '/data/anr/traces.txt'
548-554/com.example.gurucharan.mts I/dalvikvm﹕ threadid=3: reacting to signal 3
548-554/com.example.gurucharan.mts I/dalvikvm﹕ Wrote stack traces to '/data/anr/traces.txt'
548-554/com.example.gurucharan.mts I/dalvikvm﹕ threadid=3: reacting to signal 3
548-554/com.example.gurucharan.mts I/dalvikvm﹕ Wrote stack traces to '/data/anr/traces.txt'
548-554/com.example.gurucharan.mts I/dalvikvm﹕ threadid=3: reacting to signal 3
548-554/com.example.gurucharan.mts I/dalvikvm﹕ Wrote stack traces to '/data/anr/traces.txt'
548-554/com.example.gurucharan.mts I/dalvikvm﹕ threadid=3: reacting to signal 3
548-554/com.example.gurucharan.mts I/dalvikvm﹕ Wrote stack traces to '/data/anr/traces.txt'
548-548/com.example.gurucharan.mts E/pass 1﹕ connection success
548-548/com.example.gurucharan.mts E/pass 2﹕ connection success
548-548/com.example.gurucharan.mts E/Fail 3﹕ org.json.JSONException: Value