I want to make a circuit for switching on LEDs as shown in the attached picture. The circuit shown is to just depict what i want to achieve(I know this is not right). A slider which on sliding up will switch on the LEDs. If it is on the first level only one LED lights on. On the second level it should switch on both the lower and the corresponding LED and so on. I have no idea as to how to achieve this. Maybe a circuit as shown below. I really don't know anything about electronics. So a little help will be really appreciated. Thank you in advance.