I'm new to using Jquery and I need some help adding a checkbox to an already defined feildset. My code below, followed by the HTML.

function showAddress() 
	var sAddress = document.getElementById("textinput1").value;
	geocoder.geocode( { 'address': sAddress}, function(results, status) {
		if (status == google.maps.GeocoderStatus.OK) 
			document.getElementById("locBoxes").innerHTML+= "<input type='checkbox' name='checkbox3' id='checkbox3_" + bookmarksArray.length+2 + "' class='custom' value='' /><label for='checkbox3_" + bookmarksArray.length+2 + "'>" + sAddress + "</label>";
			alert("Address not found.");
HTML Code:
<fieldset data-role="controlgroup" id="locBoxes">
            <input type="checkbox" name="checkbox2" id="checkbox2_0" class="custom" value="" />
            <label for="checkbox2_0">Blossom House School</label>
            <input type="checkbox" name="checkbox2" id="checkbox2_1" class="custom" value="" />
            <label for="checkbox2_1">Cannon Hill Common</label>
            <input type="checkbox" name="checkbox2" id="checkbox2_2" class="custom" value="" />
            <label for="checkbox2_2">1 Firstway, Greater London, SW20 0JD</label>
A checkbox is created, but it's not a member of the field set. The only way I can explain it is with this pic.