Mine

on *:TEXT:!delcred*:#vhosts: {
  if (%vri. [ $+ [ $nick ] ] > 1) && ($2 isnum) && (%v. [ $+ [ $3 ] ] isnum) {
    dec %v. [ $+ [ $3- ] ] $2
    msg $chan 3Credits decreased by $2 for $3 $+ .
    halt
  }
  if ($calc($2 - %v. [ $+ [ $nick ] ]) < 0) {
    msg $chan 3You cannot set credits to a negative number! The deletion of the credits would set the credits to $calc($2 - %v. [ $+ [ $nick ] ]) $+ !
    halt
  }
  if (%vri. [ $+ [ $nick ] ] < 2) {
    msg $chan 3You do not have the required level to decrease credit!
    halt
  }
  else {
    msg $chan 3Invalid format.
    halt
  }
}