To make the event args empty to avoid the same call on next postback

I faced an issue like, I raised a postback manually through javascript for downloading a report but once it is done on every click on other controls that raises postback wasn't working properly. I got confused and browsed for sometimes to find reason of this issue. In the late evening I found solution that Event attributes should be reseted to escape from this prob. But still am searching for the reasons.

Project: .Net Application

Solution:
theForm.__EVENTTARGET.value = "";

theForm.__EVENTARGUMENT.value = "";

Though it was simple fix it made me MAD for few hours O.o