openal application with visual studio 13 c++ by using qt-5.3.1 Add-in

Question

I'm trying to do an application that plays sound with OpenAL. I'm using Visual Studio 13 c++ with qt-5.3.1 Add-in. My code doesn't give an error but there's no sound. When I debug my code, I realized that when I initialize OpenAL device remains NULL. So, context couldn't be created. I'm using this code for initializing:

 const ALCchar* devicename = alcGetString(NULL, ALC_DEFAULT_DEVICE_SPECIFIER);
    ALCdevice* Device;
    ALCcontext* Context;
    Device = alcOpenDevice(devicename);
    if (Device)
    {
        Context = alcCreateContext(Device, NULL);
        alcMakeContextCurrent(Context);
    }

    ALboolean g = alIsExtensionPresent("EAX2.0");
    alGetError();
    alcGetError(Device);

Also, I realized that when I open my app, debugger says that:

'deneme2.exe' (Win32): Loaded 'C:\Windows\System32\wrap_oal.dll'. Cannot find or open the PDB file.

'deneme2.exe' (Win32): Unloaded 'C:\Windows\System32\wrap_oal.dll'

What can be the problem? If you help me, I will be so happy. Thanks in advance.