function Call( endpoint, parameters, custom_handler, method )
{
    if ( !method ) method = "POST";

	parameters['wab_requesting_url'] = location.protocol + "//" + location.host + location.pathname;

	if ( DataStorage.Local.HasItem ( "sessionid" ) && !Call.UseXSessionIDHeader )
	{
		parameters['sid'] = DataStorage.Local.GetItem( "sessionid" );
	}

	if ( document.body.hasAttribute( "data-csrf" ) && !Call.UseXCSRFTokenHeader )
	{
		var csrf = document.body.getAttribute( "data-csrf" );

		if ( "NONE" != csrf ) parameters['wab_csrf_token'] = csrf;
	}

	var search = endpoint.indexOf( "?" );
	if ( -1 !== search )
	{
		var override_parameters = GetSearchValues.CreateDictionary( endpoint.substring( search ) );
		for ( const index in override_parameters )
		{
			parameters[index] = override_parameters[index];
		}
	}

	var command = Call.EncodeToString( parameters );
	var handler = (custom_handler) ? custom_handler : Call.DoNothing;

	if ( "http" != endpoint.substr( 0, 4 ) )
	{
		if ( "readonly:" == endpoint.substr( 0, 9 ) )
		{
			endpoint = endpoint.substring( 9 );

			switch ( endpoint.substr( 0, 3 ) )
			{
			case "/ap":
			case "/au":
				endpoint = Resolve( "ro-api" ) + endpoint;
				break;

			case "/fn":
				endpoint = Resolve( "ro-fn"  ) + endpoint;
				break;
			}
		}
		else
		{
			switch ( endpoint.substr( 0, 3 ) )
			{
			case "/ap":
			case "/au":
				endpoint = Resolve( "api" ) + endpoint;
				break;

			case "/fn":
				endpoint = Resolve( "fn"  ) + endpoint;
				break;
			}
		}
	}

	if ( 'async' in parameters && ("true" === parameters['async']) )
	{
		var httpRequest = Call.Method( method, endpoint, command, null, 0, 0 );
			httpRequest.send( command );

			handler( null, event );
	}
	else
	{
		var target = event ? event.target : null;

		//var wrapper
		//=
		//function ( responseText )
		//{
		//	handler( responseText, target );
		//}

		var httpRequest = Call.Method( method, endpoint, command, handler, 0, 0 );

		if ( DataStorage.Local.HasItem( "sessionid" ) && Call.UseXSessionIDHeader )
		{
			httpRequest.setRequestHeader( "X-Session-ID", DataStorage.Local.GetItem( "sessionid" ) );
		}

		if ( document.body.hasAttribute( "data-csrf" ) && Call.UseXCSRFTokenHeader )
		{
			var csrf = document.body.getAttribute( "data-csrf" );

			if ( "NONE" != csrf )
			{
				httpRequest.setRequestHeader( "X-CSRF-Token", csrf );
			}
		}

		httpRequest.send( command );
	}
}

Call.Method
=
function ( method, endpoint, command, handler, timeout, timeouts )
{
    return Call.CreateXMLHttpRequest( method, endpoint, command, handler, timeout, timeouts );
}

/* Deprecated */
Call.Post
=
function ( endpoint, command, handler, timeout, timeouts )
{
	return Call.CreateXMLHttpRequest( "POST", endpoint, command, handler, timeout, timeouts );
}

/* Deprecated */
Call.Get
=
function ( endpoint, command, handler, timeout, timeouts )
{
	return Call.CreateXMLHttpRequest( "GET", endpoint, command, handler, timeout, timeouts );
}

Call.CreateXMLHttpRequest
=
function( method, endpoint, command, handler, timeout, timeouts )
{
	var httpRequest = new XMLHttpRequest();
		httpRequest.open( method, endpoint, true );
		httpRequest.timeout           = timeout;
		httpRequest.timeouts          = timeouts;
		httpRequest.myEndpoint        = endpoint;
		httpRequest.myCommand         = command;
		httpRequest.myResponseHandler = handler;

		httpRequest.withCredentials = false;

		httpRequest.onreadystatechange
		=
		function()
		{
			Call.OnReadyStateChange( httpRequest, endpoint, handler );
		}

		httpRequest.ontimeout
		=
		function()
		{
			alert( "Giving up! Connection to the API server has timed out. Try again later." );
		}

		httpRequest.setRequestHeader( "Content-type", "application/x-www-form-urlencoded" );

		return httpRequest;
}

Call.OnReadyStateChange
=
function( self, endpoint, handler )
{
	var status = self.status;

	switch ( self.readyState )
	{
	case 0:
	case 1:
	case 2:
	case 3:
		break;
		
	case 4:
		switch ( self.status )
		{
		case 200:
			console.log( "Called: " + endpoint );
			if ( handler ) handler( self.responseText );
			break;

		case 404:
			console.log( "Invalid API endpoint: " + endpoint );
			break;

		case 501:
			console.log( "Required SQL Stored Procedure Not Implemented" );
			break;

		case 503:
			console.log( "Sorry, the API server is currently unavailable. Please try again later. (503)" );
			break;

		case 0:
			console.log( "The network timed out... (0)" );
			break;
			
		default:
			console.log( "Got status: " + status );
		}
		self.onreadystatechange = null;
		break;
		
	default:
		console.log( "Unexpected httpRequest ready state: " + self.readyState );
		self.onreadystatechange = null;
	}
}

Call.EncodeToString
=
function( parameters )
{
	var string = "";
	var sep    = "";

	for ( const member in parameters )
	{
		if ( "" != member )
		{
			string += sep;
			string += encodeURIComponent( member );
			string += "=";
			string += encodeURIComponent( parameters[member] );

			sep = "&";
		}
	}
	return string;
}

Call.DoNothing
=
function ()
{}