firebase query methods startAt() taking case sensitive parameters
<p>This code is working fine.</p>

<p><strong>The only improvement I want is</strong> - when I pass "Pi", it fetch all the items object that begin with the name "Pi", but when I enter "pi" it returns nothing!</p>

<p>This means I want this method <code>startAt(itemName)</code> to be worked case insensitive. So that should works with anything (lowercase or uppercase) in that case "Pi" or "pi" etc..</p>

<pre><code>//5. Get menu items from RestaurantMenu
this.getMenuItemFromRestaurantMenu = function(callback, itemName) {
  var ref_restMenu = firebase.database().ref()
  .child('Restaurants')
  .child('Company')
  .child('menu');

  //Check if item is already exist!
  ref_restMenu.orderByChild("itemName").startAt(itemName).once("value", function(snapshot) {
    var data = snapshot.val(); 
    if(data !== null) {
      //We will ger item name and restaurant id from this data.
      callback(data);
    } else {
      //Item not found in globalMenu
      console.log("%c Item not found in Global Menu", "color: red");
    }
  });
}
</code></pre>