suek,
Here is log in instructions from tengo:
http://www.tengointernet.com/hosp_how.htm#a2
As I have said before, tengo is a paid WiFi service. Your log in page should have an area where you can enter a user name and password or purchase time on tengo. I suggest you look much closer at that initial page displayed in Safari. Tapping OK when you have not complete the page will either give you no response (as you are experiencing or and error message).