function lbskg(lbsProp, kgPropName) {
	lbs = lbsProp.value;
	//  Kolla om ett numeriskt värde har skrivits
	if ((lbs == null) || (lbs == "") || (isNaN(lbs)) || (lbs < 0)) {
		alert("NOTE: Please enter a weight in pounds.");
		lbsProp.focus();
		lbsProp.select();
		return false
	}

	var lbs = Number(lbs);
	var kg = lbs * 0.45359237;
	kg = avrunda(kg,2);
	
	kgProp = document.getElementById(kgPropName);
	kgProp.value = kg;
	return true
}

function kglbs(kgProp, lbsPropName) {
	kg = kgProp.value;
	
	//  Kolla om ett numeriskt värde har skrivits
	if ((kg == "") || (isNaN(kg)) || (kg == null) || (kg < 0)) {
		alert("NOTE: Please enter a weight in kilograms.");
		kgProp.focus();
		kgProp.select();
		return false
	}

	var kg = Number(kg);

	var lbs = kg * 2.2046226;
	lbs = avrunda(lbs,2);
	
	lbsProp = document.getElementById(lbsPropName);
	lbsProp.value = lbs;
	return true
}

function avrunda(number,decimal) {
        multiplier = Math.pow(10,decimal);
        number = Math.round(number * multiplier) / multiplier;
        return number
}