For this you need to have 3 sprites for each direction. I'm just going to give oyu an example of a walking down animation. First you MUST name your sprites down1,down2, and down3. Down one should be the right foot forward, down2 should be the even feet and down3 should be left foot forward. In the key down for the card put this:
SELECT CASE KEY$
CASE DOWNARROW$
LET dir$ = "down"
WALK
END SELECT
in the open card create and move sprite "down2" to wherever you want.
Make a method called WALK with this code:
ON TIMER 10
IF animation = 3 THEN
LET animation = 1
PAUSETIMER
ELSE
LET animation = animation + 1
PUSHSPRITE 1, 0 , 7, 1
END IF
RECREATESPRITE 1, dir$ + STR$(animation)
END TIMER