I could use a simple explanation of how to deal with error handling in a COM server dll. My server is patterned after the Rick Strahl's whitepaper on the subject. As such it includes a property (lError) and a function

function error
lparameters nError,cMethod, nLine
this.cErrorMessage = ""
this.cErrorMessage = this.cErrorMessage + "<br>Error No: " + str(nError)
this.cErrorMessage = this.cErrorMessage + "<br>Method: " + cMethod
this.cErrorMessage = this.cErrorMessage + "<br>Line No: " + str(nLine)
this.cErrorMessage = this.cErrorMessage + "<br>Message: " + message() + message(1) + "<HR>"
endfunc

The other functions in the server include:
this.lError = .F.
which initializes the property. Now, what I don't quite understand is what triggers the error function and how do you get cErrorMessage returned to the calling routine, in this case it would be an ASP page. Rick tried to explain this to me but frankly the answer was too cryptic for my simple mind.

My other question is if this is the best way to handle the whole error handling business, or would it be better to use TRY/CATCH syntax in the actual server functions?

Some general instruction on this subject would certainly be appreciated.
Thanks
- Don