Hello first question how can I use the options or property of igCombo using select html tag? In this example you can see that the nullText property didn't work

<select id="Combo">
<option value="volvo">Volvo</option>
<option value="saab">Saab</option>
<option value="mercedes">Mercedes</option>
<option value="audi">Audi</option>
</select>

$(function () {

$("#combo").igCombo({

nullText:"Help"
});
});

How can i use nullText without adding <option value="-1"></option>???

Second question how can i set the backColor and the ForeColor of this igCombo