function loadJSON(callback) 
{   
	var xobj = new XMLHttpRequest();
	xobj.overrideMimeType("application/json");
	xobj.open('GET', 'http://someurl', true);
	xobj.onreadystatechange = 
		function () {
			if (xobj.readyState == 4 && xobj.status == "200") {
				callback(xobj.responseText);
			}
		};
	xobj.send(null);  
 }

 function requestJSON() 
{
	loadJSON(
		function(response) {
			data = JSON.parse(response);
		}
	);
}
 
$(document).on("click", "a", function() 
	{
		//this == the link that was clicked
		var href = $(this).attr("href");
		var href_id = $(this).attr("id");
		if (href_id == "getdata")
		{
			loadJSON(function(response) 
			{
				var div_showdata = document.getElementById('showdata');
				div_showdata.innerHTML = "Data";
				
				var content = "<ul class='box3'>";
				// Parse JSON string into object
				data = JSON.parse(response);
			
				for (var key in data)
				{
					content += ("<li>" + key + " : " + data[key] + "</li>");
				}
				content += "</ul>";
				
				//var first = "Some text";
				//var test_output = "<p>" + first + "</p>";
				div_showdata = document.getElementById('showdata');
				div_showdata.innerHTML = content;
			});
			console.log("You've clicked link:" + href);
		}
	}
);