title: select2 showing undefined while value is selected
body: <p>I am using the select2 plugin, but i am lost it does select2 the chosen value, instead it shows <code>"undefined"</code></p>
  
  <p>Here is my code, I am using the select box to bring the data from query and also search the data and bring back the json response and fill the data in the select box: </p>
  
  <p>previously i was using a hidden field and it all was working with only exception of showing <code>"undefined to selected value"</code>, the time i changed it to select, it is broken.. </p>
  
  <p>Here is my code: </p>
  
  <pre><code>&lt;select data-placeholder="Select a city" name="cities" id="cities" data-rel="selectscity"&gt;
        &lt;/select&gt;
  </code></pre>
  
  <p>JS Code</p>
  
  <pre><code>$('[data-rel="selectscity"]').select2({
          placeholderOption: 'first',
          minimumInputLength: 2,
          ajax: {
              dataType: "json",
              url: "getcities.cfm",
               data: function (term, page) {
                  return {q: term};
              },
              results: function (data) {
                  return {results: data};
              }
          },
          formatResult: formatValues,
          nextSearchTerm: displayCurrentValue,
      });
  
      function displayCurrentValue(selectedObject, currentSearchTerm) {
          return currentSearchTerm;
      }
  
      function formatValues(data) {
          return data.city + ' - ' + data.state;
      }
  </code></pre>
  
  <p>Hete is the JSON response i am getting </p>
  
  <pre><code>[{"state":"Alaska","id":622,"city":"Anaktuvuk Pass"},{"state":"Alaska","id":1141,"city":"Atqasuk"},{"state":"Alaska","id":7176,"city":"Douglas"},{"state":"Alaska","id":8783,"city":"False Pass"},{"state":"Alaska","id":13511,"city":"Kasigluk"},{"state":"Alaska","id":13512,"city":"Kasilof"},{"state":"Alaska","id":17831,"city":"Moose Pass"},{"state":"Alaska","id":27034,"city":"Unalaska"},{"state":"Alaska","id":27984,"city":"Wasilla"},{"state":"Alabama","id":205,"city":"Alabaster"},{"state":"Alabama","id":1014,"city":"Ashford"},{"state":"Alabama","id":1020,"city":"Ashland"},{"state":"Alabama","id":1055,"city":"Ashville"},{"state":"Alabama","id":4291,"city":"Castleberry"},{"state":"Alabama","id":7177,"city":"Douglas"},{"state":"Alabama","id":7724,"city":"East Tallassee"},{"state":"Alabama","id":7748,"city":"Eastaboga"},{"state":"Alabama","id":13172,"city":"Jasper"},{"state":"Alabama","id":13487,"city":"Kansas"},{"state":"Alabama","id":18629,"city":"New Castle"},{"state":"Alabama","id":19409,"city":"Notasulga"},{"state":"Alabama","id":21213,"city":"Pleasant Grove"},{"state":"Alabama","id":24547,"city":"Silas"},{"state":"Alabama","id":26111,"city":"Tallassee"},{"state":"Alabama","id":26366,"city":"Thomaston"},{"state":"Alabama","id":26372,"city":"Thomasville"},{"state":"Arkansas","id":884,"city":"Arkansas City"},{"state":"Arkansas","id":994,"city":"Ash Flat"},{"state":"Arkansas","id":1006,"city":"Ashdown"},{"state":"Arkansas","id":1600,"city":"Bassett"},{"state":"Arkansas","id":4215,"city":"Casa"},{"state":"Arkansas","id":4238,"city":"Cash"},{"state":"Arkansas","id":4258,"city":"Casscoe"},{"state":"Arkansas","id":6459,"city":"Damascus"},{"state":"Arkansas","id":7257,"city":"Drasco"},{"state":"Arkansas","id":7369,"city":"Dumas"},{"state":"Arkansas","id":7971,"city":"El Paso"},{"state":"Arkansas","id":9940,"city":"Gassville"},{"state":"Arkansas","id":11615,"city":"Hasty"},{"state":"Arkansas","id":12175,"city":"Hiwasse"},{"state":"Arkansas","id":13173,"city":"Jasper"},{"state":"Arkansas","id":15224,"city":"Little Rock Air Force Base"},{"state":"Arkansas","id":16627,"city":"Mc Caskill"},{"state":"Arkansas","id":18102,"city":"Mount Pleasant"},{"state":"Arkansas","id":18405,"city":"Nashville"},{"state":"Arkansas","id":21214,"city":"Pleasant Grove"},{"state":"Arkansas","id":21232,"city":"Pleasant Plains"},{"state":"Arkansas","id":21295,"city":"Pocahontas"},{"state":"Arkansas","id":26705,"city":"Traskwood"},{"state":"Arkansas","id":27592,"city":"Wabash"},{"state":"Arkansas","id":27597,"city":"Wabbaseka"},{"state":"Arkansas","id":27942,"city":"Washington"},{"state":"Arizona","id":995,"city":"Ash Fork"},{"state":"Arizona","id":3659,"city":"Bylas"},{"state":"Arizona","id":4217,"city":"Casa Grande"},{"state":"Arizona","id":4240,"city":"Cashion"},{"state":"Arizona","id":7178,"city":"Douglas"},{"state":"Arizona","id":9371,"city":"Fort Thomas"},{"state":"Arizona","id":14291,"city":"Lake Havasu City"},{"state":"Arizona","id":23836,"city":"Sasabe"},{"state":"Arizona","id":26604,"city":"Tonto Basin"},{"state":"California","id":510,"city":"Alturas"},{"state":"California","id":950,"city":"Aromas"},{"state":"California","id":1078,"city":"Atascadero"},{"state":"California","id":1599,"city":"Bass Lake"},{"state":"California","id":2639,"city":"Bolinas"},{"state":"California","id":3720,"city":"Calabasas"},{"state":"California","id":4245,"city":"Casmalia"},{"state":"California","id":4248,"city":"Caspar"},{"state":"California","id":4259,"city":"Cassel"},{"state":"California","id":4271,"city":"Castaic"},{"state":"California","id":4280,"city":"Castella"},{"state":"California","id":4301,"city":"Castro Valley"},{"state":"California","id":4302,"city":"Castroville"},{"state":"California","id":7186,"city":"Douglas City"},{"state":"California","id":7187,"city":"Douglas Flat"},{"state":"California","id":7648,"city":"East Irvine"},{"state":"California","id":8331,"city":"Encinitas"},{"state":"California","id":9938,"city":"Gasquet"},{"state":"California","id":10722,"city":"Grass Valley"},{"state":"California","id":11046,"city":"Guasti"},{"state":"California","id":14227,"city":"Lagunitas"},{"state":"California","id":14445,"city":"Lancaster"},{"state":"California","id":16201,"city":"March Air Reserve Base"},{"state":"California","id":17389,"city":"Milpitas"},{"state":"California","id":17548,"city":"Moccasin"},{"state":"California","id":18122,"city":"Mount Shasta"},{"state":"California","id":18185,"city":"Mountain Pass"},{"state":"California","id":18889,"city":"Newcastle"},{"state":"California","id":18958,"city":"Newport Coast"},{"state":"California","id":19010,"city":"Nicasio"},{"state":"California","id":20465,"city":"Pasadena"},{"state":"California","id":20471,"city":"Paskenta"},{"state":"California","id":20472,"city":"Paso Robles"},{"state":"California","id":21215,"city":"Pleasant Grove"},{"state":"California","id":21218,"city":"Pleasant Hill"},{"state":"California","id":21243,"city":"Pleasanton"},{"state":"California","id":21464,"city":"Port Hueneme Cbc Base"},{"state":"California","id":23557,"city":"Salinas"},{"state":"California","id":23614,"city":"San Andreas"}] 
  </code></pre>