to be called when a box object is clicked in twist2 with the arguments
dbfilename rela_x rela_y shiftkeys
GETDBFORMMODE returns a string RECORD, EDIT, LIST, QUERY or "" for the current file
GETDBFORMFIELD <fieldname> returns the field value as a string for the current record in the form/list
SETDBFORMFIELD <fieldname> <value> sets a new field value in the form and recalcs and redraws. Only in EDIT or QUERY mode. Stil buggy if value string is empty!!!!