New to development, I seek help with an applescript to access a USB->Serial adapater to allow me to send a simple text string command down the wire to the device on the other end.

I have installed the serialport x applescript extension.

Here is my applescript:
--Send a simple mode command to the K3
set the lsb to "md1;"

set thePorts to serialport list
set port_name to choose from list thePorts

	set usbserial to serialport open port_name bps rate 9600
on error theErr number errNum
	if usbserial is -1 then
		display dialog "serial port is in use " & usbserial
		return "ERROR: " & theErr & " --- " & errNum
	end if
end try

serialport write "lsb"

delay 0.25

serialport close usbserial
Here is the output:

tell application "AppleScript Editor"
	serialport list
		--> {"/dev/cu.usbserial-A70062jT", "/dev/cu.KeySerial1", "/dev/cu.USA19Hfa22P1.1", "/dev/cu.Bluetooth-PDA-Sync", "/dev/cu.Bluetooth-Modem"}
	choose from list {"/dev/cu.usbserial-A70062jT", "/dev/cu.KeySerial1", "/dev/cu.USA19Hfa22P1.1", "/dev/cu.Bluetooth-PDA-Sync", "/dev/cu.Bluetooth-Modem"}
		--> {"/dev/cu.KeySerial1"}
	serialport open {"/dev/cu.KeySerial1"} bps rate 9600
		--> -1
	serialport write "lsb"
	serialport close -1
end tell
Nothing happens, the script seems to run and close the port but the command never makes it to the other end (radio). If I use a serialport test program like this one:
everthing works, I connect to the port, and type md1; in the window and the mode changes on the radio. So it seems the only issue is getting applescript to send the serialport write command correctly?