function ClearForm(form){
  form.weight.value = "";
  form.height.value = "";
  form.bmi.value = "";
  form.my_comment.value = "";
} 
function bmi(weight, height) {
  bmindx=weight/eval(height*height)*100;
  return bmindx;
}
function checkform(form) {
  if (form.weight.value==null||form.weight.value.length==0 ||form.height.value==null||form.height.value.length==0){
    alert("\nPlease complete the form first");
    return false;
       }
  else if (parseFloat(form.height.value) <= 0||
     parseFloat(form.height.value) >=300||
     parseFloat(form.weight.value) <= 0||
     parseFloat(form.weight.value) >=200||
     isNaN(form.weight.value/eval(form.height.value*form.height.value)*100) )
     {
     alert("\nReally know what you're doing? \nPlease enter values again. \nWeight in kilos and \nheight in cm");
     ClearForm(form);
     return false;
     }
  return true;
}
function computeform(form) {
  if (checkform(form)) {
  yourbmi=Math.round(((bmi(document.getElementById('gewicht').value, document.getElementById('lengte').value/100))))/100 ;
  document.getElementById('bodymi').value=yourbmi;

  if (yourbmi >40) {
     document.getElementById('comment').value="You are grossly obese, consult your physician!";
     }
  else if (yourbmi >30 && yourbmi <=40) {
     document.getElementById('comment').value="Umm... You are obese, want some liposuction?";
     }
  else if (yourbmi >25 && yourbmi <=30) {
     document.getElementById('comment').value="You are fat, do something before it's too late";
     }
  else if (yourbmi >22 && yourbmi <=25) {
     document.getElementById('comment').value="Acceptable, but you should do some exercises";
     }
  else if (yourbmi >=20 && yourbmi <=22) {
     document.getElementById('comment').value="I envy you. Keep it up!!";
     }
  else if (yourbmi >=18 && yourbmi <20) {
     document.getElementById('comment').value="You are thin, eat more.";
     }
  else if (yourbmi >=16 && yourbmi <18) {
     document.getElementById('comment').value="You are starving. Go Find some food!";
     }
  else if (yourbmi <16) {
     document.getElementById('comment').value="Grossly undernourished, need hospitalization !! ";
     }

  if (yourbmi > 50) { yourbmi = 50;  }
  if (yourbmi < 5 ) { yourbmi =  5;  }

    yourbmi = Math.round(yourbmi);
    bmipop  = new Image(); // (157, 111);

    document.getElementById('bmipop').title = "sec_home/img2/bmi" + yourbmi + ".gif";
    // document.getElementById('bmipop').src   = "sec_home/img2/bmi" + yourbmi + ".gif";
    document.getElementById('bmipop').width = 40 + (yourbmi -10) * 3 ; // IE only !!!
    }
  return;
}