Blank Line Issue

Hi,
I have a custom report having Blank line dataitem having the following code on the OnPredataitem:
SETRANGE(Number,1, NoofBlankline);

And there is no code on the section of the Blankline trigger and there are no txtboxes.
It is just to create a blank line,so i have tried moving the above code to the OnAfterGetRecord()
as
IF ISSERVICETIER THEN BEGIN
SETRANGE(Number,1, NoofBlankline);
END;

It is actually creating blank line after certain data.
How it can be created