Why onclientclick do a postback?

I have an asp button with no onclick event but only onclientclick. Th开发者_运维知识库is call a javascript function in a iframe in which a video is playing;

each time I click the javascript function is called but also the video restart which means the page is reloaded.

How to prevent this ?

return false from your onclientclick.

OnClientClick="LoadVideo();return false;"

add

 return false;

to you function.