Update manager doesn't offer an upgrade from 11.10 to 12.04
I currently have Ubuntu 11.10 and I would like to upgrade to Ubuntu 12.04. However, Update Manager is saying "Your System is up-to-date" and "There are no updates to install." When there are things to update, it will update just fine, but it is not displaying Upgrade Now option. I checked my Update Manager settings, and it says next to "Notify me of a new Ubuntu version" that it will check "For any new version." But this is not the case, it never gives me the option to upgrade no matter how many times I click "Check." I have also tried doing the "sudo apt-get install" command in the Terminal, but that has not allowed the computer to upgrade either. What am I supposed to do?