Data entry
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-Should only be accessible to logged in admin users
-All required info must be filled up
-If "others" was selected on some fields, the field where you specificy it should be required
-If all required info is not filled up, should show an error message
-Beginning balance information, should be saved sa transactions table
-Date of last payment should be on or before the current date
-If the installment payment is empty, it should have value of 0



View ledger card
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-Should be accessible only to logged in admin users
-Show the default template of the ledger card


Retrieve a ledger card
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-Should only be accessible only to logged in admin users
-If account number exist, then we display the ledger card with transactions as well as the "new water bill" button. Personal information of the account number should be added as well.
-Transactions should be paginated. At least, 10 per page
-If not, then we display the default template of the ledger card and an error that the account number does not exist
-Full name should be displayed as follows, [Lastname], [Firstname] [Middlename]
-Balance should be updated based on the latest transaction balance
-Transactions should be sorted based on the latest billing date


New Water bill
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-Should only be accessible only to logged in admin users
-Cannot add a new water bill without a valid account number
-The water bill window, should show the current meter balance if any. If not, then don't show the meter balance
-Automatically determine the next billing covered based on the previous billing date
-Allow users to override the next billing date
-Meter reading input is required
-Current meter reading should be greater than the previous meter reading
-If meter reading inputted is invalid, the meter reading input box should appear red. If valid, display green
-Upon input of a valid meter reading the consumption, amount,total is automatically calculated but not saved to the database. (Should be saved only when save button is clicked)
-If the previous balance is not paid, then we calculate the surcharge of the previous transaction and total balance.
-If data is successfully saved, we refresh the page with the account number showing the updated transaction.
-If error when saving, we display an error message and the modal will stay and information will not be saved.