paging 2 grids in one page

I have 2 gridvi开发者_开发技巧ews in 1 page and i want to enable paging in them. now, when I want to page the first gridview to its second page, I see Its second page but the second grid view disappears.

what am I missing?

thanks.

_{Posted on behalf of the OP, the answer was left as a comment on the question}

I found the answer. when pressing 2, for example, to go to the 2nd page of 1 grid, a postback is occuring. on the Page_Load event I binded the sources to the grids only if page is not post back and thats why on of the grids disappeared all the time.