problems adding a formula

Not sure what's going wrong here but ...

I'm trying to add a simple formula to a form and am getting an error message that I can't figure out. See the coding below (I added: type = formula value = $Score - 36)

Plus_Minus
(
displayname = "Plus/Minus"
type = formula
value = $Score - 36
width = 20
maxchar = 99
tooltip = "Web application"
)

Here's the error message:

Error modifying the page
Encountered "width" at line 36, column 9.
Was expecting one of:
"value" ...
"displayname" ...
"type" ...
"tooltip" ...
"isprivate" ...
"private" ...
";" ...
"on" ...
")" ...

What am I doing wrong?
martnbeck