formatting a field

I'm trying to format a text box color using an expression
= (Field!Name.Value < 0, "Red", "Black") but system send this error
The color expression for the textbox 'Field name' contains an error
[BC30451] name 'Iff' is not declared.
Please let me know what can I douse =Iif(Field!Name.Value < 0, "Red", "Black")
"Yoya" wrote:
> I'm trying to format a text box color using an expression
> = (Field!Name.Value < 0, "Red", "Black") but system send this error
> The color expression for the textbox 'Field name' contains an error
> [BC30451] name 'Iff' is not declared.
> Please let me know what can I do