function changestlb (obj) {
  document.getElementById("kg").value=Math.round(((Number(document.getElementById("st").value * 14) + Number(document.getElementById("lb").value)) / 2.204623) *100) /100
}
function changekg (obj) {
  document.getElementById("st").value=kg2st(document.getElementById("kg").value);
  document.getElementById("lb").value=kg2lb(document.getElementById("kg").value);
}
function changeftin (obj) {
  document.getElementById("m").value=Math.round((Number(document.getElementById("ft").value * 12) + Number(document.getElementById("inch").value)) * 2.538)  /100
}
function changem (obj) {
  vinch = document.getElementById("m").value/0.02538
  document.getElementById("ft").value = Math.floor(vinch / 12)
  document.getElementById("inch").value = Math.round(vinch % 12)
}

function roundkg(kg) {
  return Math.round(kg*10)/10;
}
function kg2lb(kg) {
  return Math.round((kg * 2.204623) % 14);
}
function kg2st(kg) {
  return Math.floor((kg * 2.204623) / 14);
}

function WhatsBMI (obj) {
  BMIVal = Math.round(document.getElementById("kg").value / (document.getElementById("m").value * document.getElementById("m").value) * 10) /10;
  document.getElementById("YOURBMI").innerHTML= BMIVal;
  bestkg = document.getElementById("m").value * document.getElementById("m").value * 25
  document.getElementById("ideal").innerHTML = roundkg(bestkg);
  document.getElementById("idealst").innerHTML = kg2st(bestkg);
  document.getElementById("ideallb").innerHTML = kg2lb(bestkg);

  if (BMIVal >25) {
    tooheavybykg=roundkg(document.getElementById("kg").value-bestkg);
                XS50loss=tooheavybykg/2;
                XS70loss=tooheavybykg*7/10;
    XS50=roundkg(document.getElementById("kg").value-tooheavybykg/2);
    XS70=roundkg(document.getElementById("kg").value-tooheavybykg*7/10);
                BMI50=Math.round(XS50/(document.getElementById("m").value * document.getElementById("m").value) * 10) /10;
                BMI70=Math.round(XS70/(document.getElementById("m").value * document.getElementById("m").value) * 10) /10;
    document.getElementById("wtXS").innerHTML='<p>You are currently carrying  <b>' + tooheavybykg + 'kg (' + kg2st(tooheavybykg) + 'st ' + kg2lb(tooheavybykg) + 'lb)</b> of excess weight.</p>' ;
    if (BMIVal >26 && BMIVal <30) {
        document.getElementById("wtXSOrbera").innerHTML='<p>With a <b>BMI over 27</b>, you could consider the <b>Orbera Gastric Balloon</b> – For further information on this option please complete our <a href="contactus.php?opt=Orbera Gastric Balloon">contact form</a>.</p>';
        } else {
        document.getElementById("wtXSOrbera").innerHTML='';
        }
    document.getElementById("wtXS50").innerHTML='<p>Losing 50% of your excess weight will have the following effect:<br/><b>' + XS50 + 'kg (' + kg2st(XS50) + 'st ' + kg2lb(XS50) + 'lb) (BMI ' + BMI50 + ' kg/m<sup>2</sup>)</b>.</p>';
    document.getElementById("wtXS70").innerHTML='<p>Losing 70% of your excess weight will have the following effect:<br/><b>' + XS70 + 'kg (' + kg2st(XS70) + 'st ' + kg2lb(XS70) + 'lb) (BMI ' + BMI70 + ' kg/m<sup>2</sup>)</b>.</p>';
  } else {
    document.getElementById("wtXS").innerHTML='';
    document.getElementById("wtXSOrbera").innerHTML='';
    document.getElementById("wtXS50").innerHTML='';
    document.getElementById("wtXS70").innerHTML='';
  }
}