iif inside iif

I'd error message on this expression ,

It is written in hidden property of an image

Can you help me to correct it?

thanks all.

=iif(Parameters!Direction.Value = "none", True, iif(Parameters!Direction.Value = "Ascending",True,False )

You are missing a closing ")" and when comparing strings I would use the "equals" method.

Here is what the statement should be:

=iif(Parameters!Direction.Value.equals("none"), True, iif(Parameters!Direction.Value.equals("Ascending"),True,False ))