function initCalculateurMasse() {
	var calc = $('calculateurMasse');
	$('cliqueMetrique').getElementsByTagName("a")[0].onclick = function(){cliqueMetrique();}
	$('cliqueImperial').getElementsByTagName("a")[0].onclick = function(){cliqueImperial();}
	cliqueMetrique();
	
	calc.onsubmit = function(){
		if(this.isMetric)calculMasseMetrique();
		else calculMasseImperial();
		return false;
	}

}


function calculMasseMetrique() {
	//alert("calculMasseMetrique" + $('cm').value + $('kg').value);
	var errs = 0;
	var cm = numerize($('cm').value);
	errs += checkError($('cm'), cm);
	var kg = numerize($('kg').value);
	errs += checkError($('kg'), kg);
	
	var imc = $('imc');
	
	if(errs){
		imc.value = "";
	}else{
		var imcVal = Math.round(kg/((cm/100)*(cm/100))*100)/100;
		imc.value = imcVal;
	}
}

function calculMasseImperial() {
	var errs = 0;
	var pi = numerize($('pi').value);
	errs += checkError($('pi'), pi);
	var po = numerize($('po').value);
	errs += checkError($('po'), po);
	var lb = numerize($('lb').value);
	errs += checkError($('lb'), lb);
	var imc = $('imc');
	poToCm = 2.54;
	lbToKg = 0.45359237;
	
	if(errs){
		imc.value = "";
	}else{
		var kg = lb * lbToKg;
		var cm = (pi*12 + po)*poToCm;
		var imcVal = Math.round(kg/((cm/100)*(cm/100))*100)/100;
		imc.value = imcVal;
	}
}

function cliqueMetrique() {
	$('calculateurMasse').isMetric = true;
	$('metrique').style.display = 'block';
	$('imperial').style.display = 'none';
	addClass($('cliqueMetrique'), 'activate');
	removeClass($('cliqueImperial'), 'activate');
}

function cliqueImperial() {
	$('calculateurMasse').isMetric = false;
	$('metrique').style.display = 'none';
	$('imperial').style.display = 'block';
	removeClass($('cliqueMetrique'), 'activate');
	addClass($('cliqueImperial'), 'activate');
}

function numerize(str){
	str = str.replace(',','.');
	str = str.replace(' ','');
	str = Number(str);	
	return str;
}

function checkError(id, val){
	if(isNaN(val) || val == ''){
		addClass(id,'error');
		return 1;
	}else{
		removeClass(id,'error');
		return 0;
	}
}