Iphone not connecting to my house Wi-Fi?

I have an iphone 4 and lately it hasn't been connecting to my Wi-Fi. Everyone else's phone will connect and when my friend stays over, her's also connects. It just seems to be my phone. Any suggestions?

First, you have to go to your iPhone's settings in the main menu screen. Then, tap "Settings." After that, look at "Wi-Fi," and turn it on, or see the Wi-Fi networks, if turning it on doesn't work, or you don't know how to. After looking at the Wi-Fi networks, choose the network that is your home Wi-Fi. All those other nets listed are from houses around you, and hacking into their networks can get you in some trouble, fines, or bills. After choosing your network, tap in the password under the net. If it says, "Authentication failed," or something like that, you may have tapped in the password wrong.

The address type/key type might be wrong on your phone. To fix this (Hopefully) go to the Settings app, tap on Wi-Fi at the top. Where it shows your Wi-Fi's name on the list, there should be a arrow to the right of the name as well as the signal strength and a padlock (if there's a password on the connection). Tap on that blue arrow and you should be presented with a screen that will show you many values that you will most likely not understand. At the top of the screen, there should be a "Forget this Network" button; tap that. Going back to the Wi-Fi selection screen, tap on your home network, enter the password, and it should work. If it still does not work, go back to that screen where the blue arrow took you and where it says "IP Address" tap on DHCP to make it blue. Now, on the bottom of the same page, there should be a HTTP proxy spot, tap on "Off" unless you know you are using a HTTP proxy (It is very likely you aren't). Now once those 2 things are set, if the internet still does not work, go to the screen again where it said HTTP Proxy. Right above that should be a button saying "Renew Lease"; tap that and it should come up with a confirm tab in the bottom of the screen, tap on the white option to renew the lease. After all that is done, restart the device and it should be working.