how to make Web Page less Refreshable

Question

Dear friends,
i have a web Form in which there are controls like Textbox,Dropdownlist.
these controls have their events defined in code behind file. whenever i enter details on other controls and then enter or select any value from this autopost back control the page gets refreshed. and also it make page to Flicker
the same question is for Gridview controls also in which there are child controls like textbox and checkbox which also fires some event in code behind file.

how can i minimise the page refresh or less Flicker?

pls reply!!!
Regards,
aamir khan