<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <script src="https://cdn.jsdelivr.net/npm/vue/dist/vue.js"></script>
    <title>Title</title>
</head>


<style type="text/css">
    #lstBox1, #calcolo{
  height:300px;
  width:200px;
}

.set_input{
  display:flex;
  justify-content:center;
}

.transferBtns {
  margin-right: 30px;
  margin-left: 30px;
}

.transferBtns{
  float:left;
  align-self:center;
}
</style>
<div id="app">
<div class="set_input">
<div class="newItems">

    <b>variabili disponibili</b><br/>
            <select v-model="selected" multiple id='lstBox1'>
              <option value="ajax">Ajax</option>
              <option value="jquery">jQuery</option>
              <option value="javascript">JavaScript</option>
              <option value="mootool">MooTools</option>
              <option value="prototype">Prototype</option>
              <option value="dojo">Dojo</option>
        </select>
        <span>Selected: {{ selected }}</span>
    </div>


    <div class="newItems">
    <b>operazioni</b><br/>
           <select multiple="multiple" id='output_option'>
              <option value="+">+</option>
              <option value="-">-</option>
              <option value="/">/</option>
              <option value="*">*</option>
              <option value="**">**</option>
               <option value="(">(</option>
               <option value=")">)</option>

        </select>
    </div>

    <b>costante</b>
    <input id="costante">

<div class="transferBtns">

  <input type='button' id='btnRight' value ='  >  ' v-on:click="move_right"/>
  <br/><input type='button' id='btnLeft' value ='  <  '/>
  <div class="submitContainer">
  <input type="submit" />
  </div>
</div>
<div class="approvedItems">
        <b>variabili nel modello </b><br/>
        <select multiple="multiple" id='calcolo'>
        </select>
</div>
</div>
    </div>
</body>

<script>
new Vue({
    el: '#app',
    data: {selected: ''},
    methods: {
        move_right: function (event) {
            // `this` inside methods point to the Vue instance
            alert('Hello ' + this.name + '!')
            // `event` is the native DOM event
            alert(event.target.tagName)
        }

    }
    }
)

</script>

</html>