You can set your profit target (take profit) or loss limit (stop loss). Upon reaching these parameters your trade will be closed automatically. You can do it both at the moment of opening your trade and any time after you have opened it.
To set your profit target at the moment of opening your trade, do the following:
In the 'Open Trade' window, click the 'Loss and Profit Limits' link.
Set your loss limit and/or your profit target.
Select a direction and click the respective button.
To set your profit target and/or loss limit after you have already opened your trade, do the following:
Go to Libertex and select the trade in question from the 'My Trades' list.
In the dialog that shows up, specify the desired values and click 'Save'.