I presume you're using IE, if so try this.

1) On the tools menu click Internet options, then click the advanced tab.

2) Make sure the box next to "Disable script debugging" has a check mark in it.

3) Now make there is no check mark in the box next to "Display a notification about every script error"

4) Click apply and OK.

If that doesn't work I aint got a bloody clue!