I've read this post: Bing search API and Azure
And I used the following code to mimic it:
<?php            
if (isset($_GET['bingquery'])){
    // Replace this value with your account key
    $accountKey = '***myaccountkey***';
    $WebSearchURL = 'https://api.datamarket.azure.com/Bing/Search/v1/' + 'News?$format=json&Query=';
    $cred = sprintf('Authorization: Basic %s', base64_encode($accountKey . ":" . $accountKey) );
    $context = stream_context_create(array(
        'http' => array(
            'header'  => $cred
        )
    ));
    $request = $WebSearchURL . urlencode( '\'' . $_GET["bingquery"] . '\'');
    $response = file_get_contents($request, 0, $context);
    echo $response;
} 
?>
My AJAX call is :
var bingquery = "bingquery=" + $('#query').val();
    $.ajax({
        url: "bingsearch.php",
        method: "get",
        dataType: "json",
        data: bingquery,
        success: function(jsondata){
            console.log(jsondata); 
        }
        });
However, I still can't get back the JSON format data from Bing Search, any suggestions? Thank you so much for your help!
 
     
    