var age = document.getElementById("age");
var height = document.getElementById("height");
var weight = document.getElementById("weight");
var male = document.getElementById("m");
var female = document.getElementById("f");
var form = document.getElementById("form");
function validateForm(){
if(age.value=='' || height.value=='' || weight.value=='' || (male.checked==false && female.checked==false)){
alert("All fields are required!");
document.getElementById("submit").removeEventListener("click", countBmi);
}else{
countBmi();
}
}
document.getElementById("submit").addEventListener("click", validateForm);
function countBmi(){
var p = [age.value, height.value, weight.value];
if(male.checked){
p.push("male");
}else if(female.checked){
p.push("female");
}
form.reset();
var bmi = Number(p[2])/(Number(p[1])/100*Number(p[1])/100);
var result = '';
if(bmi<18.5){
result = 'Underweight';
}else if(18.5<=bmi&&bmi<=24.9){
result = 'Healthy';
}else if(25<=bmi&&bmi<=29.9){
result = 'Overweight';
}else if(30<=bmi&&bmi<=34.9){
result = 'Obese';
}else if(35<=bmi){
result = 'Extremely obese';
}
var h1 = document.createElement("h1");
var h2 = document.createElement("h2");
var t = document.createTextNode(result);
var b = document.createTextNode('BMI: ');
var r = document.createTextNode(parseFloat(bmi).toFixed(2));
h1.appendChild(t);
h2.appendChild(b);
h2.appendChild(r);
document.body.appendChild(h1);
document.body.appendChild(h2);
document.getElementById("submit").removeEventListener("click", countBmi);
document.getElementById("submit").removeEventListener("click", validateForm);
}
document.getElementById("submit").addEventListener("click", countBmi);