Place CMCON=7 in the top section of your code to disable analog comparators.

With A0, A1, A2 and A3 configured for analog, each pin returns 0 when the port
is read.

HIGH & LOW are read-modify-write instructions. HIGH led1 reads the whole port,
all analog pins are read-in as 0, the bit associated with led1 is set, and the whole
8-bit value is writen back to the port. So only 1 LED will ever be on.