function download( prodcode ) {

    var x = 0, y = 0;

    if ( window.screenX ) {

	x = (screen.availWidth - 400) / 2;
	y = (screen.availHeight - 400) * 0.4;

    }

    posString = 'left=' + x + ',top=' + y;

    url = '/a/download.php?prodcode=' + prodcode;
    w = window.open( url, 'DL',
		     'width=300,height=170,' + posString +
		     ',resizable=no,scrollbars=no' );

    w.focus();
}