how to simplify many OR in if statement?

From: Alan (alanchoiyimlung_at_sinatown.com)
Date: 12/23/03 

Date: Tue, 23 Dec 2003 17:56:27 +0800

I have many OR in the if statement, any method to simplify?

 if (val == 5 | val == 9 | val == 34 | val == 111 | val == 131 | .......)
    // ....

thank you