if( typeof( _tracking ) != 'object' ) {
    var _tracking = new Array();
}

// get screen dimensions
_tracking[ 'screenWidth' ] = screen.width;
_tracking[ 'screenHeight' ] = screen.height;

// get referring url
_tracking[ 'referrer' ] = escape( document.referrer );

var _trackingUrl = "http://www.otm-memorabilia.co.uk/tracker/track.php?";
var _trackingParams = new Array();

for( var param in _tracking ) {
    _trackingParams[ _trackingParams.length ] = param + '=' + _tracking[ param ];
}

_trackingUrl += _trackingParams.join( '&' );

document.write( '<script type="text/javascript" src="' + _trackingUrl + '"><\/script>' );