Writing to a file inside tell statement

Question

Ok, so I'm an AppleScript newbie.
Wanted to write a script to have some expose preferences saved to a file, and after banging my head against the table for three hours I kinda found where the "File some object wasn’t open" error was coming from. Pruned and adjusted the code to explain the above:
set theFile to (path to home folder as Unicode text) & "ExpSet"
try
set theHandle to open for access file theFile with write permission
write "First line" to theHandle
tell application "System Events"
write "Second line" to theHandle -- Here's where it dies
end tell
close access theHandle
on error errMsg number errNum
display dialog errMsg
close access theHandle
end try
The error line is just a dumb replacement for the original one, where I was doing the actual save; it needs to be inside that tell statement to be able to get the preferences that I want to save. Now, that seems to be the problem, looking at the Event Log output:
tell current application
path to home folder as Unicode text
"AQUIJADA:Users:teran:"
open for access file "AQUIJADA:Users:teran:ExpSet" with write permission
1019
write "First line" to 1019
end tell
tell application "System Events"
write "Second line" to 1019
end tell
tell current application
display dialog "System Events got an error: File some object wasn’t open."
{button returned:"OK"}
close access 1019
end tell
The first write works fine because it is before the tell "System Events" statement, but then the second one dies apparently because the write is directed to System Events and not the script itself as in the first case. Is that the way it should work? Am I missing something here or just utterly lost?
Thanks in advance!

Answer 1

When you open a file for access, it is related to the application - you haven't opened your file in System Events, so it gives you the "not open" error. Normally you should only use a tell statement for dealing with properties from that object, otherwise you run the risk of the object not knowing what you are talking about.
In your example, you can just move the write statement out of the System Events tell statement:
tell application "System Events"
      get "Second line" -- the System Events property
end tell
write the result to theHandle