I am working on a dell machine and wifi didnt work out of the box but I was able to get it to work. After doing updates the network appears in the place where you can edit connections but there is no way to connect.

When I first installed ubuntu I successfully tried this to get the wifi to work: Installing Broadcom Wireless Drivers.
.

Today I updated my system using the software updater. Now when I click on the network indicator in the top panel it just shows wired network disconnected and no wireless networks at all, like it used to.

When I click edit connections I can find "A Network" but I cannot connect just edit it.

I did what was in the link again and still no wifi.

What do I do? Please be as specific as possible, I am new to ubuntu.

Edit - I answered the post with 59^ and it is a Dell Latitude D620 and I am using ubuntu 12.04 LTS and nothing happens when I type those codes. I tried putting sudo in front of them also and still, nothing happened...