kotlov-net, а вызывается она вот так
<html><head></head><body>
<select onchange="calc()" id="hosting">
<option value="0">1</option>
<option value="1">2</option>
<option value="2">3</option>
<option value="3">4</option>
<option value="4">5</option>
</select>
<span id="padej">год</span>
Итого: <span id="result">10</span>
<script>
function calc() {
var price = 10;
var hosting = document.getElementById("hosting");
price += parseInt(hosting.options[hosting.selectedIndex].value);
result.innerHTML = price;
}
hosting.onchange=function(){
var n=(+this.value)
padej.innerHTML=n
padej.style.display= n? "block" : "none"
result.innerHTML=(+result.innerHTML)+n
}
}
</script>
</body></html>