my form code is
HTML Code:
<form name="form_case_new" method="post" action="/case/start.php" id="form_case_new">
	<fieldset>
		<legend>Case information</legend>

		<label for="name">Case Name:</label>
		<input type="text" name="name" value="" class="text" id="focus_textbox" />
		<br />
		<label for="details">Details:</label>
		<textarea rows="5" cols="50" name="details" class="text"></textarea>
		<br />
	</fieldset>

	<fieldset>
		<legend>Submit case information</legend>
		<input type="submit" name="case_new" value="Start New Case" class="button" />

	</fieldset>
</form>
my javascript is
[javascript]
document.getElementById("focus_textbox").focus();
[/javascript]

what am i doing wrong?