ISSUE-38: Window doesn\'t have alert/confirm/prompt

ISSUE-38: Window doesn't have alert/confirm/prompt

http://www.w3.org/2005/06/tracker/webapi/issues/38

Raised by: Robin Berjon
On product: Window

The current draft of Window has none of alert, confirm, or prompt, yet these can prove quite useful on 
some occasions :)

Were they excluded for a reason, or are they just simple oversights?