$(document).ready(function () {

	// if user clicked on button, the overlay layer or the dialogbox, close the dialog
	$('a.btn-ok, #dialog-overlay, #dialog-box').click(function () {
		$('#dialog-overlay, #dialog-box').hide();
		return true;
	});

	// if user resize the window, call the same function again
	// to make sure the overlay fills the screen and dialogbox aligned to center
	$(window).resize(function () {

		//only do it if the dialog box is not hidden
		if (!$('#dialog-box').is(':hidden')) popup();
	});


});

//Popup dialog
function popup(message) {

	// get the screen height and width
	var maskHeight = $(document).height();
	var maskWidth = $(window).width();

	// calculate the values for center alignment
	var dialogTop =  (maskHeight/3) - ($('#dialog-box').height());
	var dialogLeft = (maskWidth/2) - ($('#dialog-box').width()/2);

	// assign values to the overlay and dialog box
	$('#dialog-overlay').css({height:maskHeight, width:maskWidth}).show();
	$('#dialog-box').css({top:dialogTop, left:dialogLeft}).show();

	// display the message
	$('#dialog-message').html(message);

}