Problem there is no SugarCube.State.active.variables.christelevent10 there is a christelevent10a b or c but no just 10.chrome: Ctrl + Shift + J (Cmd + Option + J on Mac)
firefox: Ctrl + Shift + K (Cmd + Option + K on Mac)
then type for example: SugarCube.State.active.variables.christelevent10="false"
when you type ,"SugarCube.State.active.variables.christelevent", without the quotation marks into the console you can use the arrow keys to go through the options and set them to false like in the above example