I seem to be having issues getting DEOS and DocumentOpen to work how I assume they are supposed to!

I have set this up on a simple button to test:

setvar("VFile",DEOS("@Browseforfile","u:","*.pdf")) + alert(getvar("VFile")) + DocumentOpen(getvar("VFile"),"printer","") .

with @browseforfile, it does open the window, and has (in this case) *.pdf marked. But all files show, and it only ever opens in the last folder used, not the one I ask it to.

I have tried several different ways to use documentopen , such as preview and print.

Usually nothing happens, sometimes I get a 'could not open file' message. The file does open and has all access rights set correctly.

Is there a more detailed guide on how to use these? I have followed the documentation I could find, but fail most times. and cannot see where I am going wrong.

Paul