function MM_swapImgRestore() { //v3.0
  var i,x,a=document.MM_sr; for(i=0;a&&i<a.length&&(x=a[i])&&x.oSrc;i++) x.src=x.oSrc;
}

function MM_preloadImages() { //v3.0
  var d=document; if(d.images){ if(!d.MM_p) d.MM_p=new Array();
    var i,j=d.MM_p.length,a=MM_preloadImages.arguments; for(i=0; i<a.length; i++)
    if (a[i].indexOf("#")!=0){ d.MM_p[j]=new Image; d.MM_p[j++].src=a[i];}}
}

function MM_findObj(n, d) { //v3.0
  var p,i,x;  if(!d) d=document; if((p=n.indexOf("?"))>0&&parent.frames.length) {
    d=parent.frames[n.substring(p+1)].document; n=n.substring(0,p);}
  if(!(x=d[n])&&d.all) x=d.all[n]; for (i=0;!x&&i<d.forms.length;i++) x=d.forms[i][n];
  for(i=0;!x&&d.layers&&i<d.layers.length;i++) x=MM_findObj(n,d.layers[i].document); return x;
}

function MM_swapImage() { //v3.0
  var i,j=0,x,a=MM_swapImage.arguments; document.MM_sr=new Array; for(i=0;i<(a.length-2);i+=3)
   if ((x=MM_findObj(a[i]))!=null){document.MM_sr[j++]=x; if(!x.oSrc) x.oSrc=x.src; x.src=a[i+2];}
}

function MM_validateForm() { //v3.0
  var i,p,q,nm,test,num,min,max,errors='',args=MM_validateForm.arguments;
  for (i=0; i<(args.length-2); i+=3) { test=args[i+2]; val=MM_findObj(args[i]);
    if (val) { nm=val.name; if ((val=val.value)!="") {
      if (test.indexOf('isEmail')!=-1) { p=val.indexOf('@');
        if (p<1 || p==(val.length-1)) errors+='- '+nm+' debe ser una direccion de email.\n';
      } else if (test!='R') { num = parseFloat(val);
        if (val!=''+num) errors+='- '+nm+' debe ser un numero.\n';
        if (test.indexOf('inRange') != -1) { p=test.indexOf(':');
          min=test.substring(8,p); max=test.substring(p+1);
          if (num<min || max<num) errors+='- '+nm+' debe ser un numero entre '+min+' y '+max+'.\n';
    } } } else if (test.charAt(0) == 'R') errors += '- '+nm+' debe ser ingresado.\n'; }
  } if (errors) alert('Tiene los siguientes errores:\n'+errors);
  document.MM_returnValue = (errors == '');
}

function formatCurrency(num) {
         num = num.toString().replace(/\$|\,/g,'');
         if(isNaN(num))
         num = "0";
         sign = (num == (num = Math.abs(num)));
         num = Math.floor(num*100+0.50000000001);
         cents = num%100;
         num = Math.floor(num/100).toString();
         if(cents<10)
            cents = "0" + cents;
         for (var i = 0; i < Math.floor((num.length-(1+i))/3); i++)
             num = num.substring(0,num.length-(4*i+3))+'.'+
         num.substring(num.length-(4*i+3));
         return (((sign)?'':'-') + '$ ' + num + ',' + cents);
}


function Calcular(){
        var COSTOBENZ = parseFloat(document.formcalcula.pnafta.value);
        var COSTOMET = parseFloat(document.formcalcula.pgnc.value);
        var KMLIT = parseFloat(document.formcalcula.kmlitro.value);
        var KMANNO = parseFloat(document.formcalcula.kmanual.value);

        var A =( COSTOBENZ / KMLIT )  * KMANNO;
        var C = ( COSTOMET / (KMLIT*1.138) )  * KMANNO;
        var D = A - C;

        document.formcalcula.gnafta.value=formatCurrency(A);
        document.formcalcula.ggnc.value=formatCurrency(C);
        document.formcalcula.ahorro.value=formatCurrency(D);
}