>SET ORDER TO tagname
>
>>i hv two file (a.dbf, a.cdx) , inside a.cdx i hv three index expression~
>>how do i control to open the index expression?

Have a look at the SET INDEX Command. You can open .idx and .cdx in a list seperated with commas in any order you like.

>>and, i know the cdx file will open automatically when the same name .dbf file open. but i need to active different index expression to control different display!