Try setting the multiple attribute on the select element:
<select id="businessFn" name="businessFn" style="width: 225px" multiple>
<option value="1" >one</option> |________Here
<option value="2" selected ='selected' >Two</option>
<option value="3" >Three</option>
<option value="4" selected ='selected' >four</option>
<option value="5" >five</option>
</select>