javascript deselect checkbox when deselecting another checkbox

I would like to have the possibility with javascript to deselect checkbox "demo2" when I deselect checkbox "demo1". only deselect

<input type="checkbox" name="demo1" value="Bike">
<label for="vehicle1"> I have a bike</label><br>
<input type="checkbox" name="demo2" value="Car">
<label for="vehicle2"> I have a car</label><br>