CComBST - > LPCTSTR

[bobetko]

I am trying to convert CComBST type to LPCTSTR type and I am using this code

CComBSTR myParam = "url=";
CComBSTR myLoc;
m_spWebBrowser2->get_LocationURL(&myLoc);
myParam.Append(myLoc);
_bstr_t bstrInterm(myParam);
MessageBox(NULL, (LPCTSTR)bstrInterm, "", NULL);

But compiler is giving me error:
error C2065: '_bstr_t' : undeclared identifier

What I am doing wrong?
I tried to include comutil.h, but that only produced some other erors.

I am using ATL.

Where can I learn more about these types: BSTR, CComBSTR, LPCTSTR, LPCSTR, etc.... getting lost here....


Thanks.