Rolling months display

Hi All,

My requirement is such that the charts and cross tabs should display rolling 13 months from the selected month in the dropdown.

My dropdown code at startup is:

DROPDOWN_1.setItems(DS_1.getMemberList("0CALMONTH",MemberPresentation.Text,MemberDisplay.Key,13));

DROPDOWN_1.setSelectedValue(DS_1.getVariableValueExt("ZE_CALMON"));

On select code of dropdown is:

DS_1.setFilter("0CALMONTH",DROPDOWN_1.getSelectedValue());

But am not getting the rolling 13 months on selecting a calendar month in dropdown. Charts show data only for that particular date selected.

Please can you let me know what should be the solution.

Thanks & Regards

Swasti