cannot connect to wifi!

[kachmeifucan]

hi im a noob here. been having problems connecting to Wifi services. i would be able to connect (as in it would show the wifi connection name in the home screen) but i would still not be able to connect! the wifi logo is white and when i check manage connections the wifi box is ticked but not showing a check sign instead it shows (-). what do i need to do??? appreciate your help. thanks!