How to move an entire block of code right or left by one Tab

When I insert an IF/ENDIF or similar code in a previously formatted program I go through and either add or remove a tab on each line in the block of code between the newly inserted or deleted IF/ENDIF.

Is there a way to move the entire block of code to keep the formatting as it should be? I'm not aware of how to do this.

Highlight the whole block of lines you want to move.

Then TAB to move right; SHIFT-TAB to move left.