JimEvans: Correcting the error introduced in r15643 that throws an exception when an unhandled alert is present. Modal dialogs created by showModalDialog() aren't alerts; they're windows in their own right.
JimEvans: Correcting the error introduced in r15643 that throws an exception when an unhandled alert is present. Modal dialogs created by showModalDialog() aren't alerts; they're windows in their own right.

r15807

krosenvold/selenium-git-release-candidate,krosenvold/selenium-git-release-candidate,krosenvold/selenium-git-release-candidate,krosenvold/selenium-git-release-candidate,krosenvold/selenium-git-release-candidate,krosenvold/selenium-git-release-candidate,krosenvold/selenium-git-release-candidate,krosenvold/selenium-git-release-candidate