Edit in JSFiddle

var btn = document.getElementById("btn");
var result = document.getElementById("result");
btn.onclick = function(){
   var val = 'smtg';
result.innerHTML = 'Value is ' + (val === 'smtg') ? 'Something' : 'Nothing';
}

<p>点击查看结果：</p>
<button id="btn">查看结果</button>
<p>结果：</p>
<div id="result"></div>

p {
    font-size: 14px;
    height 24px;
    line-height: 24px;
}