<!--
function co2(fd, fu, i) {
  var ac = new Array(0.11,0.18,0.10,0.047,0.04,0.074,0.29,0.64,0.30,0.31);
  if (fu=='Mi') {mu=1.61;} else {mu=1;}
  var ct = 0;
  switch (i) {
    case 1: if (fd>3000) ct=0; else ct=1; break; // air
    case 2: ct=2; break; // bus
    case 3: ct=3; break; // ferry
    case 4: ct=4; break; // rail
    case 5: ct=5; break; // cruise
    case 6: ct=6; break; // car
    case 7: ct=7; break; // road freight
    case 8: ct=8; break; // helicopter
    case 9: ct=9; break; // household
  }
  return (fd * mu * ac[ct]);
}
function compute(f,i) {
  var fr = parseInt(f.amount.value);
  var fru = 'Km';
  if (i!=9) if (f.units[0].checked) fru='Km'; else fru='Mi';
  var r = 0; if (fr>=0 && fru!='') r+=co2(fr,fru,i);
  if (isNaN(r) || (r<0)) { f.amount.value=''; f.result.value=''; alert('Enter a number greater than zero'); } else { f.result.value=parseFloat(r,2); }
}
function computeCost(f) {
  var x = 8.50;
  var t;
  t = f.amount.value * x/1000; // x is minimum per tonne
  if (t<x) t=x;
  if (isNaN(t) || (t<0)) {
    f.amount.value = '';
	f.result.value = '';
	alert('Enter a number greater than zero');
  }
  else {
    f.result.value = parseFloat(t,2);
  }
}
function objectClear(o) { document.getElementById(o).style.border = '1px inset #B6B6B6;'; }
function objectError(o) { document.getElementById(o).style.border = '1px inset #B62125;'; }
function isNonZeroInteger(p) {
  var re=/^[1-9]{1,}[0-9]*$/
  return re.test(p);
}
function isNonZeroReal(p) {
  var re=/^[0-9]{1,}\.[0-9]*$/
  return re.test(p);
}
function isInteger(p) {
  var re=/^[0-9]*$/
  return re.test(p);
}
//-->