Addition of rows

Hi All;

Below is my expression = IIf( (Fields!Date.Value)<=(Parameters!EndDate.Value),sum( Fields!hours1.Value),0 )

which gives me the result 

Instead of getting this result in multiple line i wanted it to get in one single line with addition of rows i.e 60 + 70

i used group by but it displayed 0 

Any help much appreciated

Thanks

Pradnya07