please help to make sample or solve my issue

please help to make sample or solve my issue

thanks for your kind reply i have an application and i make two forms one for stock and other for sale , but i unable to connect each form data

my form link is
http://creator.zoho.com/mozatonline/mobile/

for example :

in first form that is for my shop stock i make three field product name, price, quantity i use formula price * quantity

in second form that is for sale record i make three fields product name, price, quantity but how the quantity will decrease from 1st form data after submitting this sale form? i mean how my stock quantity from 1st form will decrease when i submit second form that is for sale ????

also tell me the payment method to upgrade my zoho creator account
please help me in thiss issue i will wait for your kind reply May God bless zoho team its really a good work i have ever seen all credit goes to zoho team work