Problème en javascript

function convertirTemperatureCelsius()
{	
	var celsius = document.getElementById('celsius');
	var fahrenheit = document.getElementById('fahrenheit');
	var kelvin = document.getElementById('kelvin');
	var rankine = document.getElementById('rankine');
	var reaumur = document.getElementById('reaumur');
	var romer = document.getElementById('romer');
	var delisle = document.getElementById('celsius');
	var newton = document.getElementById('newton');
	
	
	//Fahrenheit
	var fahrenheitAConvertir = parseFloat(celsius.value);
	var resultatFahrenheit = ((9.0/5.0) * fahrenheitAConvertir) + 32.0;
	
	fahrenheit.value = resultatFahrenheit;
	
	
	//Kelvin
	var kelvinAConvertir = parseFloat(celsius.value);
	var resultatKelvin = kelvinAConvertir + 273.15;

	kelvin.value = resultatKelvin;
}