<a href="http://oauth.vk.com/authorize?client_id=3983087&redirect_uri=http://net.lead100.ru/publications/vklogin.php&response_type=code" title="test">Vk</a>

<script src='http://code.jquery.com/jquery-1.8.3.min.js'></script>
<script type='text/javascript'>

$(document).ready(function () {

                    $.ajax({
                        type: 'GET',
			      	
                        url: 'https://oauth.vk.com/access_token/',
		        data: 

{ 
client_id:'3983087', 
		 	client_secret : '0jNrw2bHdLPcQkF1x3an',
code:'".$_REQUEST['code']."',
redirect_uri:'http://net.lead100.ru/publications/vklogin.php'
}


,
                        
                        dataType: 'json', 

			success: function (json) {

}
});
});

</script>