designing of an electronic counter

Hi,
I want to designing a counter so as to count people entering into a toilet.I am thinking of using IR emitter and phototransistor for person detector circuit. My problem is how to arrange them so as the perfect detection will be achieved and the counter will count.
Please can any one help me
Thanks

Posted by lucy (fortunataj@yahoo.co.uk) on 14/05/2004, at 15:41 GMT