dll function call.

Could someone tell me what i am doing wrong. I am trying to use gget() function but the bot crashes every time: 15/05/2014 19:20:34.394 | Crashed in OnTick with DllNotFoundException: Unable to load DLL 'sample.dll': The specified module could not be found. (Exception from HRESULT: 0x8007007E)

It is a c++ dll. 
Here is the code:

using System;
using System.Linq;
using cAlgo.API;
using cAlgo.API.Indicators;
using cAlgo.API.Internals;
using cAlgo.Indicators;
using System.Runtime.InteropServices;

class Test
{
    [DllImport("sample.dll")]
    public static extern int gget(out double[] c);

}
namespace cAlgo
{
    [Robot(TimeZone = TimeZones.UTC, AccessRights = AccessRights.None)]
    public class NewcBot : Robot
    {
        [Parameter(DefaultValue = 0.0)]
        public double Parameter { get; set; }

        protected override void OnStart()
        {
            // Put your initialization logic here
        }

        protected override void OnTick()
        {
            double[] arr;
            Test.gget(out arr);
            Print(arr[0]);
            // Put your core logic here
        }

        protected override void OnStop()
        {
            // Put your deinitialization logic here
        }
    }
}