W3Schools Tryit Editor

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<h1>Change user-select with JavaScript</h1>
<p>Click the "Try it" button to set the user-select property of the p element to "none":</p>
<button>Try it</button>
<p id="demo">After you click on the button, it is not possible to select the text of this p element (try to double-click me before and after).</p>
</div><div class="naked_ctrl">
<form action="/index.cgi/contrast" method="get" name="gate">
<p><a href="http://altstyle.alfasado.net">AltStyle</a> によって変換されたページ <a href="https://www.w3schools.com/cssref/tryit.php?filename=trycss3_js_user-select">(->オリジナル)</a>
/ <label>アドレス: <input type="text" name="naked_post_url" value="https://www.w3schools.com/cssref/tryit.php?filename=trycss3_js_user-select" size="22" /></label> <label>モード: <select name="naked_post_mode">
<option value="default">デフォルト</option>
<option value="speech">音声ブラウザ</option>
<option value="ruby">ルビ付き</option>
<option value="contrast" selected="selected">配色反転</option>
<option value="larger-text">文字拡大</option>
<option value="mobile">モバイル</option>
</select>
<input type="submit" value="表示" />
</p>
</form>
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