Display Nothing in table column heding when parameter doesn't have any value

Hi,

I created one tabular report . Report has 2 parameters(ex: A and B) both have default values from two different datasets. I am using these parameters in two column headings (col1 has parameter A and col2 has parameter B) in report. My question is, if parameters(A and B ) don't have any value from the datasets it should display "Nothing" in the table column headings(col1 and col2). If parameters(A & B) have some value(June & July respectively) it should display in table column headings(col1 and col2).

Thanks in advance,

Visu