I found the part the causes problem: if I use a variable instead of a value in the where cause it won't work. For example:

CLIENT = 'test'
TEMP = "Select clClientID from CLIENTTYPE where clClientID = CLIENT"
?SQLEXEC(gnquoteConn,TEMP,"Qt_num")
It will return -1.

TEMP = "Select clClientID from CLIENTTYPE where clClientID = 'test'"
?SQLEXEC(gnquoteConn,TEMP,"Qt_num")
it will work.
any idea. thanks
sherry