<!DOCTYPE html>
<form class="calculator" id="calculator">
Тариф:<br/>
<label><input type="radio" name="radio_tariff" value="tariff1" checked=""/>ОСН</label><br/>
<label><input type="radio" name="radio_tariff" value="tariff2"/> УСН (6%)</label><br/>
<label><input type="radio" name="radio_tariff" value="tariff3"/>УСН (15%)</label><br/>
<br/>
Операции<br/>
<select name="operation">
<option>текст</option>
<option>текст</option>
<option>текст</option>
<option>текст</option>
<option>текст</option>
<option>текст</option>
</select>
<br/>
<output name="result">0</output>
<script>
(function() {
var tariffs = {
tariff1: [7200,10300,14500,19400,23000,29000],
tariff2: [4200,7800,10900,15700,18100,24200],
tariff3: [5400,9000,12100,16900,20500,26600]
};
var form = document.querySelector('#calculator');
var output = form.querySelector('[name="result"]'); // form.result
form.onchange = function() {
var selectedTariff = form.querySelector('input[name="radio_tariff"]:checked').value;
output.innerHTML = tariffs[selectedTariff][form.operation.selectedIndex];
};
// initialization
form.onchange();
})()
</script>
</form>