The Undo button on the Toolbar reverses the last action you performed. For instance, if you accidentally delete a source from the Timeline, just click Undo to restore it. Clicking the black triangle on the Undo button displays a list of actions that you have performed in Video Edit Magic. Clicking on an action in this list nullifies the effects of all the actions that you had performed after that action (and that action). This is a useful feature if you wish to undo a bunch of commands using a visual interface. The subsequent actions that were nullified are available to you only if you don’t perform a fresh action at this point. Once you perform a fresh command, the list begins afresh from that point forwards and all the subsequent commands (their effect on your project) are nullified permanently. You can also select an action (or set of actions) that you have undone, and reverse the reversal by using the Redo button on the Toolbar.
One way of undoing a recent command is to click Edit > Undo. You may use Edit > Undo as many times as you wish to nullify the effects of your commands in a sequential, manner, backtracking each preceding command, step by step.
To sequentially redo your undone commands, click Edit > Redo. You will not be able to redo an undone command if you issue a fresh command after the undo operation. The number of Redo operations available to you is equal to the number of Undo operation that you have performed.