why is the first page shown after deletion in datagrid in asp.net

i done exactly a swas said to delete record in datagrid. but after, the deletion i am taken back to the first page,rather than :
1.previous page, if that record was the last one on the page.
2.the same page , if there were other record also.

same is the case with insertion and edit. why is the first page shown. what should i do to avoid this??????
pls help, REALLY URGENT!!!!!!!!!!!!