javascript to > jquery

i have a script like:

<script>
function vatCalculation() {
    var netto = document.getElementById('netto').value;
    var lordo = parseFloat(parseFloat(netto) / parseFloat(0.8)).toFixed(2);
    var ritenuta = parseFloat(parseFloat(lordo) * parseFloat(0.2)).toFixed(2);

    document.getElementById('lordo').value = lordo;
    document.getElementById('ritenuta').value = ritenuta;
}
</script>

and the html is:

<input name="netto" id="netto" type="number" maxlength="20" min="0" placeholder="00.00" onchange="vatCalculation();" />

<input name="lordo" id="lordo" type="text" maxlength="20" min="0" placeholder="00.00" readonly="true" />

<input name="ritenuta" id="ritenuta" type="text" maxlength="20" min="0" placeholder="00.00" readonly="true" />

Now the value of var are showed inside the field, but if i want tho show it inside <h1></h1> tag, what i need to to? Need to use jQquery? (fore live results). What can i do?