Help Problem with Wi-Fi

[Orlas112]

Hello, i bought this S3 4 daus ago. My operator plan, provides for me only 1gb data usage. Now i used in 3 days 600mb.. If i use over 1gb, i'll need to pay each 1mb very expensive.. I have at home wifi interner, using it on laptop, i am suing my GS3 to search it, i find it, enter password, it writes Saved, Secured. I off data usage from my mobile operator, but now i cant go to internet, it writes no data connection.. But i want use wifi at home.. i entered correct password, but my telephone is not using wifi... wtf?