JSFiddle - React, Tailwind, and code Playground
by dixalex
HTML
<select id="selectbox" name="name">
<option value="">Please select...</option>
<option value="Elvis">Elvis</option>
<option value="Frank">Frank</option>
<option value="Jim">Jim</option>
</select>
<input type="text" id="first-textbox" name="firstname" value="Elvis" oninput="document.getElementById('second-textbox').value=this.value">
<input id="second-textbox" type="text" name="firstname" value="">
JavaScript
//StackOverflow Solution: http://stackoverflow.com/questions/32238975/two-textbox-same-value-in-jquery
//Disable Input: http://stackoverflow.com/questions/1414365/disable-enable-an-input-with-jquery
//Source: http://jsfiddle.net/nafnR/727/ by Rafael Topasi
//08-26-2015
$(document).ready(function () {
$("input#first-textbox").prop('disabled', true);
//$("input").prop('disabled', false);
$("#selectbox option").filter(function () {
return $(this).val() == $("#first-textbox").val();
}).attr('selected', true);
$("#selectbox").on("propertychange change", function () {
$("#first-textbox").val($(this).find("option:selected").attr("value"));
$("#second-textbox").val($(this).find("option:selected").attr("value"));
});
});