Verification of voucher
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When a user clicks on exchange zone button the following will take place
1. a pop up will appear for the user click on a button "exchange zone", the fields on pop is "enter voucher code" and submit button (this voucher codes are stored in the dbase)
2. the minimum amount in the voucher should not be less than $50 ( if amt is less than $50 print on screen "voucher balance is less than $50)
4. voucher code should expire on 28th of every month , i mean all vouchers
3. No other user should enter the same voucher code in a given month ( if an expired voucher code is entered print on screen " voucher has expired"
5. if all conditions is satisfied then submit the form and the date in which the form was submitted.