D-Link DIR 601 - Dlink Wireless N 150 Home Router Product Manual page 96

Secton  - Connectng to a Wreless Network
3. Enter the same security key or passphrase that is on your router
and click Connect.
It may take 20-30 seconds to connect to the wireless network. If the
connection fails, please verify that the security settings are correct.
The key or passphrase must be exactly the same as on the wireless
router.
D-Lnk DIR-601 User Manual