how do i make checkboxes like radio button

I'm having difficulty using jquery to make the checkboxes act like radio so I can only check one of the three checkboxes

<legend>Choose your delivery option!</legend>
                <label><input type="checkbox" id="delivery" name="delivery" value="standard" />Standard Delivery</label>
                <label><input type="checkbox" id="delivery" name="delivery" value="2day" />2 Day Shipping</label>
                <label><input type="checkbox" id="delivery" name="delivery" value="overnite" />Overnight Shipping</label>