JSFiddle - React, Tailwind, and code Playground
by seymorevenue
HTML
<form id="form_id" onsubmit="return false;">
<table>
<thead>
<th>Services</th>
</thead>
<tbody>
<tr>
<td>Virus Removal</td>
<td><input type="checkbox" name="compitem" value="20" onclick="addition(this)"/>$20<br></td>
</tr>
<tr>
<td>System Clean Up</td>
<td><input type="checkbox" name="compitem" value="20" onclick="addition(this)"/>$20<br></td>
</tr>
<tr>
<td>Driver Updates</td>
<td><input type="checkbox" name="compitem" value="20" onclick="addition(this)"/>$20<br></td>
</tr>
<tr>
<td>Fix Registry Errors</td>
<td><input type="checkbox" name="compitem" value="20" onclick="addition(this)"/>$20<br></td>
</tr>
<tr>
<td>Hardware Updates</td>
<td><input type="checkbox" name="compitem" value="20" onclick="addition(this)"/>$20<br></td>
</tr>
<tr>
<td>Cable Management</td>
<td><input type="checkbox" name="compitem" value="20" onclick="addition(this)"/>$20<br></td>
</tr>
<tr>
<td> <button onclick="addition();">total?</button></td>
</tr>
</tbody>
</form>
<span id="totalSpan">0</span>
JavaScript
var sum = 0;
function addition(param)
{
if (param.checked == true)
sum += parseInt(param.value);
else
sum += -parseInt(param.value);
docoument.getElementById("totalSpan").innerText = sum;
}