change alt-tab to ctrl-tab on ubuntu 12.04

I have an apple USB keybord for my Ubuntu 12.04. I remapped command left key to control for convenience. And now I switch between apps with Alt+Tab and between tabs within one app with Ctrl+Tab. It's normal but not comfortable and painless.

It would be ideally to remap shortcuts as opposite: Ctrl+Tab - switching between apps, Alt+Tab - between tabs. Can I do it? xmodmap?

UPDATE: here is a screenshot of settings which I apply, restarted but it hasn't changed:

You can change your Keyboard Settings from System >> Keyboard >> Shortcuts.

Under Navigation, you should see "Switch Application". You can click it and set the new short cut as you want. Hope it helps.

For certain Keyboard shortcuts you need to also edit these in dconf-tools. At least on 12.04.

Install dconf-tools and start dconf-editor.

Navigate to org/gnome/desktop/wm/keybindings and change the "switch-windows" key.