server.ScriptTimeout in global.asax

I am using a simulation of windows server to make some automatic database updates and sendling emails. The code I got from this article:

http://www.codeproject.com/KB/aspnet/ASPNETService.aspx

Some of the application running from global.asax are very heavy, and I have to set server.ScriptTimeout = 600.
My problem is that I don't understand where to put this server.ScriptTimeout.
I tried in the sub of the application, but then the application doesn't run anymore.
I tried also in global.asax in Sub Application_Start, but still no result.

I can see that the application is running, if I don't use server.ScriptTimeout. It make some updates, but there is not time enough to finish.

Where should I put the server.scriptTimeout?
...