How do i trap error from mappoint ?

I am trying to find addresses and pushpin it . But, I need a way to check whether the address is valid in mappoint or not, before calling findaddresresults.

(valid address is working fine.) But i have some junk in my database. It gives a pb error ' Error accesing external function....'

I am calling mappoint with address parameter as a separate application. ( not OLE)

TIA
Roopa