Iphone 4s will not connect to home wifi network

[taylorstewart]

When I first bought my wireless router and connected my computer and Iphone 4s it worked great.  I have since had to reset my wireless router several times and I can no longer connect my Iphone 4s to the wireless network. 

My computer will connect to the network just fine.  I use the 8 digit pin number on the back of the router to connect the computer.  When I try and connect my Iphone 4s to the network using this 8 digit pin number, My phone says that it is "unable to connect to the network"

My computer will connect to my wireless network, but my Iphone will not!  Please help