As I said You can not redirect to another page without postback.
However there is trick which you can use for a better user experience, Do remember, it would not avoid the postback but it would not cause any flicker in your screen. You can place these two tags at the head of your HTML dcocument :-
<META http-equiv="Page-Enter" content="blendTrans(Duration=0.2)">
<META http-equiv="Page-Exit" content="blendTrans(Duration=0.2)">
One more thing, these code might not work in some browsers. but In IE it will work.
Good luck.