Edit in JSFiddle

// Safari reports success of list attribute, so doing ghetto detection instead
yepnope({
  test : (!Modernizr.input.list || (parseInt($.browser.version) > 400)),
  yep : [
      'https://raw2.github.com/CSS-Tricks/Relevant-Dropdowns/master/js/jquery.relevant-dropdown.js',
      'https://raw2.github.com/CSS-Tricks/Relevant-Dropdowns/master/js/load-fallbacks.js'
  ]
});

              
            
          
            
              
                
<input type="text" list="countries" name="mycountry" />

<datalist id="countries">
	<select>
		<option value="Afghanistan">Afghanistan</option>
		<option value="Albania">Albania</option>
		<option value="Algeria">Algeria</option>
		<option value="Andorra">Andorra</option>
		<option value="Angola">Angola</option>
		<option value="Antigua &amp; Deps">Antigua &amp; Deps</option>
		<option value="United Kingdom">United Kingdom</option>
		<option value="United States">United States</option>
		<option value="Uruguay">Uruguay</option>
		<option value="Uzbekistan">Uzbekistan</option>
		<option value="Vanuatu">Vanuatu</option>
		<option value="Vatican City">Vatican City</option>
		<option value="Venezuela">Venezuela</option>
		<option value="Vietnam">Vietnam</option>
		<option value="Yemen">Yemen</option>
		<option value="Zambia">Zambia</option>
		<option value="Zimbabwe">Zimbabwe</option>
	</select>
</datalist>