I can change Pool-Name in unlang after if condition but if i use Group-Name for change the group of user it not work ....!!!

in 

authorize {

sql
if (notfound) {
update control {
Auth-Type := "Accept"
Group-Name := "Bad-User"
}
}

In rad group check table i define  " Bad-User     :=       Pool-Name       Bad-User-Pool "


do i have any mistake in unlang ?