Cálculo de los intereses
Compatibilidad:
Ms Internet Explorer
,
Netscape
Calculadora financiera de formulario HTML
[
Muestra el ejemplo práctico
]
el código para insertar en tu página
<!-- w w w . h t m l p o i n t . c o m --> <HTML> <HEAD> <!-- Código descargado gratuitamente de HTMLpoint, el sitio italiano del web publishing http://www.htmlpoint.com --> <TITLE>Ejemplos Javascript: ejemplo práctico </TITLE> <SCRIPT LANGUAGE="JavaScript"> <!-- hide this script tag's contents from old browsers function checkNumber(input, min, max, msg) { msg = msg + " field has invalid data: " + input.value; var str = input.value; for (var i = 0; i < str.length; i++) { var ch = str.substring(i, i + 1) if ((ch < "0" || "9" < ch) && ch != '.') { alert(msg); return false; } } var num = parseFloat(str) if (num < min || max < num) { alert(msg + " not in range [" + min + ".." + max + "]"); return false; } input.value = str; return true; } function computeField(input) { if (input.value != null && input.value.length != 0) input.value = "" + eval(input.value); computeForm(input.form); } function computeForm(form) { if ((form.payments.value == null || form.payments.value.length == 0) || (form.interest.value == null || form.interest.value.length == 0) || (form.principal.value == null || form.principal.value.length == 0)) { return; } if (!checkNumber(form.payments, 1, 480, "# of payments") || !checkNumber(form.interest, .001, 99, "Interest") || !checkNumber(form.principal, 100, 10000000, "Principal")) { form.payment.value = "Invalid"; return; } var i = form.interest.value; if (i > 1.0) { i = i / 100.0; form.interest.value = i; } i /= 12; var pow = 1; for (var j = 0; j < form.payments.value; j++) pow = pow * (1 + i); form.payment.value = (form.principal.value * pow * i) / (pow - 1) } function clearForm(form) { form.payments.value = ""; form.interest.value = ""; form.principal.value = ""; } <!-- done hiding from old browsers --> </SCRIPT> </HEAD> <BODY bgcolor="white"> <FORM method=POST> <TABLE border> <TR> <TD><DIV ALIGN=CENTER> # of<br>Payments</DIV></TD> <TD><DIV ALIGN=CENTER>Interest<br>Rate</DIV></TD> <TD><DIV ALIGN=CENTER>Principal</DIV></TD> <TD> </TD> <TD><DIV ALIGN=CENTER> Monthly<br> Payment</DIV></TD> </TR> <TR> <TD><INPUT TYPE=TEXT NAME=payments SIZE=5 onChange=computeField(this)> </TD> <TD><INPUT TYPE=TEXT NAME=interest SIZE=6 onChange=computeField(this)> </TD> <TD><INPUT TYPE=TEXT NAME=principal SIZE=9 onChange=computeField(this)> </TD> <TD> </TD> <TD><INPUT TYPE=TEXT NAME=payment SIZE=9 onChange=computeField(this)> </TD> <TD><INPUT TYPE="button" VALUE="Compute" onClick=computeForm(this.form)> </TD> <TD><INPUT TYPE="reset" VALUE="Reset" onClick=clearForm(this.form)> </TD> </TR> </FORM> <FORM method=POST> <TR> <TD><INPUT TYPE=TEXT NAME=payments SIZE=5 onChange=computeField(this)> </TD> <TD><INPUT TYPE=TEXT NAME=interest SIZE=6 onChange=computeField(this)> </TD> <TD><INPUT TYPE=TEXT NAME=principal SIZE=9 onChange=computeField(this)> </TD> <TD> </TD> <TD><INPUT TYPE=TEXT NAME=payment SIZE=9 onChange=computeField(this)> </TD> <TD><INPUT TYPE="button" VALUE="Compute" onClick=computeForm(this.form)> </TD> <TD><INPUT TYPE="reset" VALUE="Reset" onClick=clearForm(this.form)> </TD> </TR> </FORM> <FORM method=POST> <TR> <TD><INPUT TYPE=TEXT NAME=payments SIZE=5 onChange=computeField(this)> </TD> <TD><INPUT TYPE=TEXT NAME=interest SIZE=6 onChange=computeField(this)> </TD> <TD><INPUT TYPE=TEXT NAME=principal SIZE=9 onChange=computeField(this)> </TD> <TD> </TD> <TD><INPUT TYPE=TEXT NAME=payment SIZE=9 onChange=computeField(this)> </TD> <TD><INPUT TYPE="button" VALUE="Compute" onClick=computeForm(this.form)> </TD> <TD><INPUT TYPE="reset" VALUE="Reset" onClick=clearForm(this.form)> </TD> </TR> </TABLE> </FORM> </CENTER> </body> </html> <!-- w w w . h t m l p o i n t . c o m -->
[
Baja en un único archivo .zip,
las imágenes y demás archivos necesarios
para el funcionamiento de los script de esta sección]
