how do i select 4 squares. for example
ina grid with 20 squares when i click square 1, square 2, square 3, and square 4 they are selected, not moved or something just selected. and later i click other squares for example like square 5 , sq 6 , sq 7 and sq 8. when i click sq 8 they swap positions. sq1 goes to sq 5 and sq 5 goes to sq 1's positions. and so with others.