for i=1 to m.lCount
	lnSum = evaluate('curtemp.' + sumfields[m.i,1]) + evaluate('m.'+sumfields[m.i,1])
	try
		replace ('curtemp.' + sumfields[m.i,1]) with m.lnSum in curtemp
	catch to oError when oError.ErrorNo = 39
		messagebox("lnSum = " + transform(m.lnSum) + " for field " + sumfields[m.i,1])
		...
	endtry
endfor

>>

type("m.oError")

Why don't you process error in the CATCH clause? Also in

catch to oError   &&&  when .t. isn't necessary

>>
>>
>Thanks a lot, Sergey. I overlooked " because I switched from vartype. How should I process this error in CATCH block?
>
>Thanks a lot again.