Summary field in Page header.

Hi all,

I want to display a summary field(maximum of a date field ) in a page header.I tried using formulas and running totals.Everything gives the perfect answer wen it is placed in the footer.When I place it in the header it is giving the first record.

So i tried to sort the records in descending order to get the first record as maximum.Now the problem is

I am having Null values for date field.I can not filter those records at report level since i need other columns of the records for calculations.

I want the null values to go down of all the records wen sorted.

can anyone please help me?

Thanks & Regards,

Hema.