Andrus,

I cannot make it work with searchfield omitted either, even with the comma to indicate its positional absence.

However, the Hacker's Guide suggests that the SearchField parameter is IGNORED when the fourth parameter is coded. I confirmed that it does run that way.

So, to answer your question, it looks like you must put any valid field name in SearchField when you want to code cTagName.

I do think that the error presented by omitting (content) of the third parameter is a VFP error.

Cheers

JimN

>From VFP help:
>
>LOOKUP(ReturnField, eSearchExpression, SearchedField, cTagName)
>
>I cannot understand the meaning of third parameter, if fourth
>parameter is present.
>
>If I specify cTagname, eSearchExpression is searched using tag cTagname
>and there is no any need to use SearchedField.
>
>What in this case I must put to SearchedField ?
>
>If I leave SearchedField empty, error occurs. Is this an illegal
>VFP design ?