Need to refresh the tiltle bar variable of ALV Grid

Hi All,

I have a ALV grid output in which i am displaying the no of records( example 10 ) in the title bar with a variable.....

I also have a refresh functionality in my report in which if i click refresh button, sometimes i will filter out the output and show the output in which the no of entries may decrease ( example 7 ).....

But even now my title bar variable shows the old value ( example 10 ).....How can i refresh the title bar value which i am passing through one of the layout variable.....