function usufrutto(){
//usufrutto versione 2.0
//copyright Alessandro Reggiani  2001 - 2004 All rights reserved

var aa = (document.modulo.eta.value).replace(".","").replace(".","").replace(",",".")

var bb = (document.modulo.immob.value).replace(".","").replace(".","").replace(",",".")
var cc = (document.modulo.usu.value)

var a = parseFloat(aa)
var b = parseFloat(bb)
var c = parseFloat(document.modulo.usu.value)

if(a <= 20){document.modulo.usu.value = Math.round(100*(b / 100 * 2.5 * 38.0))/100}
if(a > 20 && a <= 30){document.modulo.usu.value = Math.round(100*(b / 100 * 2.5 * 36.0))/100}
if(a > 30 && a <= 40){document.modulo.usu.value = Math.round(100*(b / 100 * 2.5 * 34.0))/100}
if(a > 40 && a <= 45){document.modulo.usu.value = Math.round(100*(b / 100 * 2.5 * 32.0))/100}
if(a > 45 && a <= 50){document.modulo.usu.value = Math.round(100*(b / 100 * 2.5 * 30.0))/100}
if(a > 50 && a <= 53){document.modulo.usu.value = Math.round(100*(b / 100 * 2.5 * 28.0))/100}
if(a > 53 && a <= 56){document.modulo.usu.value = Math.round(100*(b / 100 * 2.5 * 26.0))/100}
if(a > 56 && a <= 60){document.modulo.usu.value = Math.round(100*(b / 100 * 2.5 * 24.0))/100}
if(a > 60 && a <= 63){document.modulo.usu.value = Math.round(100*(b / 100 * 2.5 * 22.0))/100}
if(a > 63 && a <= 66){document.modulo.usu.value = Math.round(100*(b / 100 * 2.5 * 20.0))/100}
if(a > 66 && a <= 69){document.modulo.usu.value = Math.round(100*(b / 100 * 2.5 * 18.0))/100}
if(a > 69 && a <= 72){document.modulo.usu.value = Math.round(100*(b / 100 * 2.5 * 16.0))/100}
if(a > 72 && a <= 75){document.modulo.usu.value = Math.round(100*(b / 100 * 2.5 * 14.0))/100}
if(a > 75 && a <= 78){document.modulo.usu.value = Math.round(100*(b / 100 * 2.5 * 12.0))/100}
if(a > 78 && a <= 82){document.modulo.usu.value = Math.round(100*(b / 100 * 2.5 * 10.0))/100}
if(a > 82 && a <= 86){document.modulo.usu.value = Math.round(100*(b / 100 * 2.5 * 8.0))/100}
if(a > 86 && a <= 92){document.modulo.usu.value = Math.round(100*(b / 100 * 2.5 * 6.0))/100}
if(a > 92 && a <= 99){document.modulo.usu.value = Math.round(100*(b / 100 * 2.5 * 4.0))/100}
if(a > 99){document.modulo.usu.value = "valore età errato"}

document.modulo.nuda.value  = Math.round(100*(bb - document.modulo.usu.value))/100


var xxx = document.modulo.usu.value
var xxx1 = Decimale(xxx.toString())
document.modulo.usu.value = xxx1

var yyy = document.modulo.nuda.value
var yyy1 = Decimale(yyy.toString())
document.modulo.nuda.value = yyy1

}

//function errore(){
//var x =  document.modulo.immob.value
//var y = x.indexOf(",")
//if(y > -1){document.write("<center><strong><font size=6 face=arial color=red>ERRORE !</font><br><br><font face=arial size=3>Hai utilizzato la virgola, invece del punto, per separare i centesimi dagli euro.</font></strong><br><br><form action=usufrutto.html method=GET><input type=submit value='TORNA INDIETRO'</form><br><br>")}
//var z = x.indexOf(".")
//var w = x.length
//var t = w - z
//if(t > 3 && z > -1){document.write("<center><strong><font size=6 face=arial color=red>ERRORE !</font><br><br><font face=arial size=3>Hai utilizzato il punto per separare le migliaia.</font></strong><br><br><form action=usufrutto.html method=GET><input type=submit value='TORNA INDIETRO'</form><br><br>")}
//}