JSFiddle - React, Tailwind, and code Playground

by SchmalzyB

HTML

<form>
    <select id="domainvalue" onchange="toggleLogOnButton()">
        <option selected disabled value="Blank">Select Domain...</option>
        <option value="NA">NA</option>
        <option value="AP">AP</option>
        <option value="EU">EU</option>
        <option value="EXT">EXT</option>
    </select>
    <input id="Log_On" type="submit" value="Log On" onclick="alert('SUBMITED');"></input>
</form>

CSS

#domainvalue {
    width: 150px;
    height: 26px;
}

#Log_On {
    padding: 4px 8px;
}

JavaScript

var toggleLogOnButton = function(){
    var selectDomain = document.getElementById("domainvalue");	
    var logOnButton = document.getElementById("Log_On");

    logOnButton.disabled = (selectDomain.value == 'Blank');
};

(function() {
    toggleLogOnButton();
})();