how to auto select an input field and the text in it on page load

From http://www.codeave.com/javascript/code.asp?u_log=7004:

var input = document.getElementById('myTextInput');
input.focus();
input.select();
<input id="myTextInput" value="Hello world!" />

In your input tag, place the following:

onFocus="this.select()"

try this. this will work on both Firefox and chrome.

<input type="text" value="test" autofocus="autofocus" onfocus="this.select()">