finger print scan and processing in website

the program in the website should take the fingerprints of the person with the attached external fingerprint scanner (bio-metric scanner) and calculate logic with some numbers and displays some result (logic=will be explained later on .results= will given with logic ) i hope you understand for every finger print ..our system shows some output that is noting but "result". well if the same fingerprint is scanned ..again somewhere else .from another device/computer...the thumb impression has to be checked from the previous database saved (if yes = show output = previous result) it should be attached with a payment gateway ....that's all ...