Not to my surprise: I goofed up

I had mix up with the hash indexes: had to add an identifier for location. Which in dutch is a "lokatie". Coming from a dutch database the fields have dutch like names, like "idblok" for "base location identifier". I wrote it in english: "idbloc" which gave me a null vallue.

Case solved... ty all for your thoughts on the problem... found out adding the extra debugging info