My Blackberry doesnt connect to wifii automatically ;( ?

[janki]

Hi guys my bb bold 9900 use to be good, well not good but atleast ok.But since past one year it has bedn giving me wifii trouble.I dnt have internet on my phn I csnt afford it.Anyway everytime I leave my house for college andcome back I have to restart my phn so it can connect to th wifii.It doesn't connect until I doso.Please help its relli.annoying.I have tried deleting the network and doing it again but doesn't seem.to work.I have also ttied reset setting bt it didn't wofk.eithef.It didn't use to be like this before.Please help guys any ideas suggestions are most welcome.Thank.you.