Hiding duplicate data values on SSRS reports or setting the Visible field parameter using an expression

I have a report that I want to hide data when it is the same as the record above it, and display it when it is different.

So the Visible property for the field on the report would be conditional.  I have tried using an expression using Previous(same field value).  I must be doing something wrong as it is not working.

Here is the expression I pasted in the Visible field property.

if(Fields!ORDER_NBR.Value = Previous(Fields!ORDER_NBR.Value), FALSE, TRUE)

Assistance would be greatly appreciated - thanks in advance.

Carol