APEX

Hi,
I have 2 DatePicker, 1 button and 1 report. Source for Datepicker i put 'SQL Query' Type : Select sysdate from dual
and Select sysdate-7 from dual. The report (standart type) only contain 4 column with a filter of Datepicker :
Select A, B, C, D From x
Where date between :From and :To
The button only for submitting the query so the report will show the data. Well, the output so far so good.
Now the situation here is, after i change the date and click the button to show the data, when i click on one of the sort column, the page seems to "refresh" and the datepicker Back to default value based on the source. In this case i cant see the filter data anymore. (Only happens when Sorting and clicking the pagination).
Any idea to make the date not changing ?

Thanks.
Gamez