Basic use of Select option in ASP .Net

<select id="unit" style="width: 100px;">
                                    <option value="UNIT_KILOMETER">Kilometers</option>
                                    <option value="UNIT_FOOT">Feet</option>
                                    <option value="UNIT_STATUTE_MILE">Miles</option>
                                    <option value="UNIT_METER">Meters</option>
                                    <option value="UNIT_NAUTICAL_MILE">Nautical Miles</option>
                                    <option value="UNIT_US_NAUTICAL_MILE">US Nautical Miles</option>
                                    <option value="UNIT_DEGREE">Degrees</option>
                                </select>