/* File name: cc_calculator.js Authored by: Loic Kreitmann Date authored: 08/17/2001 Modified by: Loic Kreitmann Date last modified: 08/22/2001 Description: Credit Card Interest Calculator Functions for Visa USA */ //APR var APR = 0; //purchase amount var purchaseAmount = 0; //balance var balance = 0; //Monthly payment amount var moPayAmnt = 0; //monthly percentage rate var moPercRate = 0; //monthly interest var moInt = 0; //initial monthly payment var initMoPay = 0; //months to pay off var moToPay = 0; //principle var princ = 0; //average monthly finance charge var avgMoFin = 0; //Total finance charges var totFinance = 0; //total cost var totCost = 0; //function grabs the values of the form fields and makes the necessary calculations function storeVariables() { if (numbersValidator("credit_card_calc","apr") && numbersValidator("credit_card_calc","purchase_amount") && numbersValidator("credit_card_calc","pay_per_m")) { APR = Number(document.credit_card_calc.apr.value); purchaseAmount = Number(document.credit_card_calc.purchase_amount.value); initMoPay = (purchaseAmount * (APR / 100)) / 12; //purchaseAmount * 0.02; moPayAmnt = Number(document.credit_card_calc.pay_per_m.value); if (APR > 100) { alert("Your annual percentage rate\ncannot be greater than 100%."); document.credit_card_calc.apr.value = ""; document.credit_card_calc.apr.focus(); } else if (purchaseAmount == 0) { alert("What is your purchase amount?"); document.credit_card_calc.purchase_amount.value = ""; document.credit_card_calc.purchase_amount.focus(); } else if (moPayAmnt == 0) { alert("Please enter the amount you\nplan to pay per month."); document.credit_card_calc.pay_per_m.value = ""; document.credit_card_calc.pay_per_m.focus(); } else if (moPayAmnt < initMoPay) { alert("Sorry, the monthly payment entered is\nsmaller than the required approximate\nminimum payment of $" + (Math.round(initMoPay * 100) / 100) + ".\n----------------------------------\nPlease enter a monthly payment\ngreater than $" + (Math.round(initMoPay * 100) / 100) + "."); document.credit_card_calc.pay_per_m.value = ""; document.credit_card_calc.pay_per_m.focus(); } else { var count = 0; moPercRate = Math.round((APR / 12) * 100) / 100; princ = moPayAmnt; balance = purchaseAmount; do { moInt = (balance * (APR / 100)) / 12; princ = moPayAmnt - moInt; balance = balance - princ; totFinance += moInt; count++; } while (balance > 0); moToPay = count; avgMoFin = Math.round((totFinance / count) * 100) / 100; displayResults(); } } } //function displays the results function displayResults() { var str1 = ""; var str2 = ""; var str3 = ""; var str4 = ""; str1 += "\n"; str1 += "\n"; str1 += "\n"; str1 += "\n"; str1 += "\n"; str1 += "\n"; str1 += "\n"; str1 += "\n"; str4 += "\n"; str4 += "

\n"; str1 += "

Los resultados de tus cálculos aparecen más abajo. Imprime esta página y úsala como una referencia útil. ¿Quieres intentarlo de nuevo? Regresa a la planilla de cálculos.

\n"; str2 += "\n"; str2 += "\n"; str2 += "\n"; str2 += "\n"; str2 += "\n"; str2 += "\n"; str2 += "\n"; str2 += "\n"; str2 += "\n"; str2 += "\n"; str2 += "\n"; str2 += "\n"; str2 += "\n"; str2 += "\n"; str2 += "\n"; str2 += "\n"; str2 += "\n"; str2 += "\n"; str2 += "\n"; str2 += "\n"; str2 += "\n"; str2 += "\n"; str2 += "\n"; str2 += "\n"; str2 += "\n"; str2 += "\n"; str2 += "\n"; str2 += "\n"; str2 += "\n"; str2 += "\n"; str2 += "\n"; str3 += "\n"; str3 += "\n"; str3 += "\n"; str3 += "\n"; str3 += "\n"; str3 += "\n"; str3 += "\n"; str3 += "\n"; str3 += "\n"; str3 += "\n"; str3 += "\n"; str3 += "\n"; str3 += "\n"; str3 += "\n"; str3 += "\n"; str3 += "\n"; str3 += "\n"; str3 += "\n"; str3 += "\n"; str3 += "\n"; str3 += "\n"; str3 += "\n"; str3 += "\n"; str3 += "\n"; str3 += "\n"; str3 += "\n"; str3 += "\n"; str3 += "\n"; str3 += "\n"; str3 += "\n"; str3 += "\n"; str3 += "\n"; str3 += "\n"; str3 += "\n"; str3 += "

	$\"A.\"$	Tasa de porcentaje anual (APR)		" + APR + "	%
$\"B.\"$	Cantidad total de la compra	$	" + purchaseAmount + "
$\"C.\"$	Cantidad que planeas pagar cada mes	$	" + moPayAmnt + "
$\"D.\"$	Tasa de porcentaje mensual		" + moPercRate + "	%
$\"E.\"$	Pago mínimo mensual inicial aproximado	$	" + initMoPay + "
$\"F.\"$	Número de meses para terminar de pagar		" + moToPay + "
$\"G.\"$	Cargo financiero promedio mensual	$	" + avgMoFin + "
$\"H.\"$	Total de cargos financieros	$	" + (Math.round(totFinance * 100) / 100) + "
$\"I.\"$	Costo total del artículo	$	" + (Math.round((totFinance + purchaseAmount) * 100) / 100) + "

\n"; str4 += "

Todos los cálculos de esta página contemplan que no hay un período de gracia, que la tasa mensual de acumulación se basa en 30 días por mes y 360 días por año, y que el cargo de financiamiento mensual se basa en el saldo final del mes anterior.

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Recuerda: Las diferentes tarjetas tienen términos diferentes. Tus resultados de la hoja de trabajo de la tarjeta de crédito podrían variar, dependiendo de los términos específicos de tu tarjeta.

\n"; str4 += "

\n"; str4 += "\n"; str4 += "\n"; document.write(str1 + str2 + str3 + str4); }