Handling Current Page Index in DataGrid

Question

HI I have a datagrid bind to DataTable, on a page i have one combo (having two Items) which filters the data in datagrid through Combo box selection. If i selects the first item it gives me around 100 records which are spread into 10 pages of datagrid. at run time i use paging and moves to the 9th page of datagrid. Then i selects the second option in combo which gives only 10 records in datatable (means the 1 page of datagrid), on this selection it through an error of CurrentPageIndex. the error is :- 'Invalid CurrentPageIndex value. It must be >= 0 and < the PageCount ' I am using the server.transfer to reselect the the Data of Datatable after combo box item selection. Amit