preventing deletion of linefeds

[Viktoras Didziulis]

can anybody suggest a simple method to prevent users deleting linefeeds in a
text field when pressing backspace or delete keys. It should allow deletion
of any other symbol which is not "return" and should not use table object at
all. 
 
What should be added into the handler below? 
Chunk expression (word 2 of the selectedchunk) > 1 does not work... 
 
on backspaceKey 
if ??? then 
pass backspaceKey 
end if 
end backspaceKey 
 
BW 
Viktoras