how do i write script(vb, java) to close

1. i’d like to run a script to close the current opened window(browser)
this is the code i tried
javascript:self.close()
but there is a message pop up confirming if i really want to close the window, how would i do to get rid of this confirmingmessage(i did write with even onclick).

2. is there anyway to call java script which is not in the even. for example if user came
i got one page when user click the link to another web page, which is open new windows,
with this new window i would check something
if the checking is not match i just want this new window to be closed, how would i implement java script (or vbscript or both) to do the task for me

thanks in advance for any help