function HttpConnection( oProperties )
{
	this.Properties = oProperties;
	this.SetXmlHttpObject();
	if ( this.XmlHttpObject == null )
		return;

	// Set default properties
	if ( this.Properties.asynchronous == null ) this.Properties.asynchronous = true;
	if ( this.Properties.method == null ) this.Properties.method = 'GET'; 

	// Append query string to prevent browser cache problems
	this.AppendQuerystring( escape( new Date() ) );
}

HttpConnection.prototype.AppendQuerystring = function( sProperty, sValue )
{
	if ( this.XmlHttpObject == null )
		return;

	this.Properties.queryString = ( !this.Properties.queryString ) ? '?' : this.Properties.queryString + '&';
	this.Properties.queryString += sProperty;
	if ( sValue != null && sValue != '' )
		 this.Properties.queryString += '=' + sValue;
}

HttpConnection.prototype.GetResponse = function()
{
	if ( this.XmlHttpObject == null )
		return;

	if ( this.Properties.asynchronous && this.XmlHttpObject.onreadystatechange == null )
		throw 'HttpConnection.GetResponse: Please set the asynchronous flag to false, or first set a callback method using SetCallbackMethod()';

	if ( !this.Properties.asynchronous && top.oCanvas != null )
		top.oCanvas.OpenWaitDialog( 'De opdracht wordt verwerkt, een moment geduld...' );

	this.Properties.method = this.Properties.method.toUpperCase();
	switch ( this.Properties.method )
	{
		case 'POST':
			this.XmlHttpObject.open( this.Properties.method, this.Properties.url, this.Properties.asynchronous );
			this.XmlHttpObject.setRequestHeader( "Content-Type", "application/x-www-form-urlencoded; charset=UTF-8" );
			this.XmlHttpObject.send( this.Properties.queryString );
			break;
			
		case 'GET':
			this.XmlHttpObject.open( this.Properties.method, this.Properties.url + this.Properties.queryString, this.Properties.asynchronous );
			this.XmlHttpObject.send( null );
			break;

		default:
			throw 'Invalid HTTP request method \'' + this.Properties.method + '\'';
	}

	if ( !this.Properties.asynchronous )
	{
		// TODO: Check if this.XmlHttpObject.status is 200, otherwise handle error

		if ( top.oCanvas != null )
			top.oCanvas.CloseWaitDialog();

		// Return response text
		return this.XmlHttpObject.responseText;
	}
}

HttpConnection.prototype.SetCallbackMethod = function( mMethod, oParams )
{
	if ( this.XmlHttpObject == null || mMethod == null ) 
		return;

   var xmlHttpObject = this.XmlHttpObject;
	xmlHttpObject.onreadystatechange = function() 
	{
		// TODO: Check if this.XmlHttpObject.status is 200, otherwise handle error

		mMethod( xmlHttpObject, oParams ); 
	}
}

HttpConnection.prototype.SetXmlHttpObject = function()
{
	/*@cc_on @*/
	/*@if (@_jscript_version >= 5)
	// JScript gives us Conditional compilation, we can cope with old IE versions.
	// and security blocked creation of the objects.
	try { this.XmlHttpObject = new ActiveXObject( "Msxml2.XMLHTTP" ); }
	catch ( e ) 
	{ 
		try { this.XmlHttpObject = new ActiveXObject("Microsoft.XMLHTTP"); } 
		catch ( E ) { this.XmlHttpObject = null; } 
	}
	@end @*/
	if ( this.XmlHttpObject == null && typeof XMLHttpRequest != 'undefined' )
		try { this.XmlHttpObject = new XMLHttpRequest(); } catch ( e ) { this.XmlHttpObject = null; }
	if ( this.XmlHttpObject == null && window.createRequest )
		try { this.XmlHttpObject = window.createRequest(); } catch ( e ) { this.XmlHttpObject = null; }
}