scheme online interpreter
http://jscheme.sourceforge.net/jscheme/src/jlib/demo/Demorunner.html
try this:

(define (count lis ele)

  (cond((null? lis) 0)

       ((eq? (car lis) ele) (+ 1 (count (cdr lis) ele)))

       (else (count (cdr lis) ele)))

  )

)



(count '(a b c d a a) 'a)