DXL broadcastmessage

I am trying to create a simple DXL script to run before my archiving script to warn users to get out of DOORS.
I have not written any DXL before and get an error when running the following:

string sendBroadcastMessage(string msg)
if (null sendBroadcastMessage("Administrators test"))

The error is -R-E- DXL: <Line:2> forward reference not resolved

What do I need to do to fix this?
SystemAdmin - Mon Dec 03 11:23:22 EST 2012

Re: DXL broadcastmessage
llandale - Mon Dec 03 18:23:44 EST 2012

string ErrMess = sendBroadcastMessage("Exit DOORS. Administrators test")
if (!null ErrMess) then ack(ErrMess)

Re: DXL broadcastmessage
SystemAdmin - Tue Dec 04 04:49:54 EST 2012

llandale - Mon Dec 03 18:23:44 EST 2012
string ErrMess = sendBroadcastMessage("Exit DOORS. Administrators test")
if (!null ErrMess) then ack(ErrMess)

Thank you! That worked perfectly!