VC++ 2003: stack corrupted around variable

Hi,
i am using some working code from an already existing example program. I use Visual C++ 2003. Here is the method i am using:

Code:

void CIDAdmin::CStrToUchar(CString str, UCHAR *ucBuffer, ULONG *ulBufferLen)
{
	int Length = 0;
	int DataLength = 0;
	char cstr[] ="";
	char strcstring[512] ="";
	byte hexval=0x00;
	int i = 0;
	
	Length = str.GetLength();
	
	for (i = 0; i<Length; i++)
		strcstring[i] = str.GetAt(i);
	
	DataLength = Length / 2;
	for (i = 0; i<DataLength; i++)
	{
		cstr[0] = strcstring[2*i];
		cstr[1] = strcstring[2*i+1];
		sscanf( cstr, "&#37;02x", &hexval );
		ucBuffer[i]=hexval;
		
	}
	
	*ulBufferLen = DataLength;	
}//CStringToUchar

and when i run my program, i get "run-time check failure #2 - Stack around the variable 'cstr' was corrupted", which refers to the "char cstr[] =""; " of the method above i think. If i try to bypass the error, i also get "run-time check failure #2 - Stack around the variable 'hexval' was corrupted", which refers to the "byte hexval=0x00; ". The only differences -i have noticed so far- is that in my project, i use the "atlstr" header and my compiler and linker settings also differ from the example program... Any ideas?

Thanks

Code:

char cstr[] = "";

This declares a char buffer exactly one byte in size. Obviously, that isn't big enough.

Stack corruption around a variable happens when you thrash the memory (hence overwrite the bounds of your array on the stack).