JSFiddle - React, Tailwind, and code Playground

by Nick Karnik

HTML

// one
    <select id="s1" onchange="handleSelection(this, s2)">
<option>Select</option>
<option value="1">one</option>
<option value="two">two</option>
<option>three</option>
    </select>

//two
    <select id="s2" onchange="handleSelection(this, s1)">
<option>Select</option>
<option value="1" >one</option>
<option value="two">two</option>
<option>three</option>
    </select>

JavaScript

function handleSelection(source, dest) {

    source.options[source.selectedIndex].disabled=true;
    dest.options[source.selectedIndex].disabled=true;
}