html input get number

1
2
3<form id="frm1" action="Calculate.html">
4    <table width="350px" border="1px">
5        <tr>
6            <th colspan="2">Availability</th>
7        </tr>
8        <tr>
9            <td>Total Production Time</td>
10            <td>
11                <input type="number" id="TotalProductionTime" placeholder="">hours</td>
12        </tr>
13        <tr>
14            <td>Breaks</td>
15            <td>
16                <input type="number" id="Breaks" placeholder="">minutes</td>
17        </tr>
18        <tr>
19            <td>Malfunctions</td>
20            <td>
21                <input type="number" id="Malfunctions" placeholder="">minutes</td>
22        </tr>
23        <tr>
24            <td>Theoretical production time:</td>
25            <td>
26                <p id="test"></p>
27            </td>
28        </tr>
29    </table>
30    <input type="button" onclick="Calculate()" value="calculate">
31</form>
32
33
34function Calculate() {
35    var TotalProductionTime = document.getElementById("TotalProductionTime").value;
36    var TotalProductionTimeInMinutes = TotalProductionTime * 60;
37    var Breaks = document.getElementById("Breaks").value;
38    var Malfunctions = document.getElementById("Malfunctions").value;
39    var TheoreticalProductionTime = TotalProductionTimeInMinutes - Breaks - Malfunctions;
40
41    document.getElementById("test").innerHTML = TheoreticalProductionTime;
42}