Setting the Last-Error Code

The fax service provider (FSP) functions return a Boolean value that indicates the success or failure of the function. If the function fails, the fax service calls the GetLastError function to retrieve extended error information.

When a function fails, the FSP must call SetLastError immediately to set the last-error code. If the FSP calls another Microsoft Win32 function after setting the last-error code, that function can overwrite the FSP's last-error code.