Convert C++ into VC 2005

I'm new to C++ but trying to compile some code into a Dll but i get the
following errors when compiling the code

Error 1 error C2440: 'default argument' : cannot convert from 'const char
[1]' to 'CString' k:\c++ kode\sb5dll-1\sb5dll-1\station_source\queues.h 20
Error 2 fatal error C1903: unable to recover from previous error(s);
stopping compilation k:\c++ kode\sb5dll-1\sb5dll-1\station_source\queues.h
27

here is a part of the code where the error appears

#if !defined(AFX_QUEUES_H__B593B58B_7E9A_4FAA_8D9C_D5A1F251E8E0__INCLUDED_)

#define AFX_QUEUES_H__B593B58B_7E9A_4FAA_8D9C_D5A1F251E8E0__INCLUDED_

#if _MSC_VER > 1000

#pragma once

#endif // _MSC_VER > 1000

#include "TcpClient.h"

//#include "Constants.h"

/****************/

class CQueAlert : public CObject

{

public:

CQueAlert(int AlertID, int LockID, CString AlertDesc = ""); here it points
to

virtual ~CQueAlert() {};

void CreateMsg(CTcpClient *pTcpClient);

int m_AlertID;

int m_LockID;

CString m_AlertDesc;

};

If I make the empty "" to " " then it moves in to the next char in Cstring
and pop up with the same errors.

PetterL