https://stackoverflow.com/a/2874745/335565
HTML
<input type="text" id="disabled" value="disabled" />
<input type="text" id="readOnly" value="readOnly" />
<input type="text" id="readonly" value="readonly" />
CSS
input {
display: block;
text-align: center;
width: 64px;
}
JavaScript
document.getElementById('disabled').disabled = true
document.getElementById('readOnly').readOnly = true
document.getElementById('readonly').readonly = true