Please follow the below steps
1) press menu button
the mobile will search for available access points and ask you to browse.connect to the network and then you can select the site and go ahead
If the wifi network is not password secure then u should b able to connect to the network provided the signal is strong.just check the settings for Wlan.I have the same phone with no problem with network having a strong signal.just click the searched network with out password and it should connect.
CHECK WHEATHER YOUR PHONE HAS WI-FI OPTION?