iTunes Sync Xcode .ipa app Failed to Sync

I recently made a iOS app and w开发者_JAVA百科anted to try it on my iPod Touch but iOS 5 is not supported with Xcode 4.1 so I made my app into a .ipa and emailed it to my home computer and put it on iTunes I synced my iPhone and it was going fine but when it reached the end it said

"Itunes Sync

AppName failed to install"

Please help me or tell me if there any webpages out there,

Thanks!

---

You have to export your private key of your Apple Developer account and import it to your home computer. Download developer certificate using xCode or from Provisioning Portal.

You must have valid provisioning profile to install unpublished apps.