 <p>I was able to slightly improve Zach's answer by incorporating a few function calls. The problem with that answer is that it disables onMouseUp completely, thereby preventing you from clicking around in the textbox once it has focus.</p> <p>Here is my code:</p> <pre><code>&lt;input type="text" onfocus="this.select()" onMouseUp="javascript:TextBoxMouseUp();" onMouseDown="javascript:TextBoxMouseDown();" /&gt; &lt;script type="text/javascript"&gt; var doMouseUp = true; function TextBoxMouseDown() { doMouseUp = this == document.activeElement; return doMouseUp; } function TextBoxMouseUp() { if (doMouseUp) { return true; } else { doMouseUp = true; return false; } } &lt;/script&gt; </code></pre> <p>This is a slight improvement over Zach's answer. It works perfectly in IE, doesn't work at all in Chrome, and works with alternating success in FireFox (literally every other time). If someone has an idea of how to make it work reliably in FF or Chrome, please share. </p> <p>Anyway, I figured I'd share what I could to make this a little nicer.</p>