hi every body ; the problem i have is very important for me to get the
solution and i do hope that u all of my friend will help basically we sell
the products that contain the serial numbers and all of our business is
running on that particular serial number suppose i have keep the record of
each product serial number that i sell and i will keep the record of the
unsold serial number as well.let me give the example the item i purchased and
then some of them sold so what stock will be in my hand then

for example : purchases

item Quanity Serial Start
Serial End
Cobra 40 56710093200
567100093239

let's suppose if i sell the serial number

item quantity serial start
serial End
Cobra 10 56710093220
567100093229

now i want to know which serial is left in stock with me

regards
gul