function frameScroll( ) {

	var oFrame = document.getElementById( "frame" );
	var oImages = document.getElementById( "content-images" );
	var oTexts = document.getElementById( "texts" );

//-- UITLEG BEREKENING OPACITY -->
//-- var nOpacity = Math.max( 0, 1 - ( oFrame.scrollTop / ( oImages.offsetHeight - oFrame.offsetHeight ) * [IN TE STELLEN WAARDE] ) );
//-- 
//-- VOORBEELDEN[IN TE STELLEN WAARDE]:
//-- * 0.5 => na volledige scrollbar 50% transparant
//-- * 1   => na volledige scrollbar volledig transparant
//-- * 2   => na 1 / 2 scrollbar volledig transparant
//-- * 4   => na 1 / 4 scrollbar volledig transparant

	var iScrollTop = getScrollTop( );
	var iClientHeight = getClientHeight( );

	var nOpacity = Math.max( 0, 1 - ( iScrollTop / ( oImages.offsetHeight - iClientHeight ) * 2 ) );
	var iOpacity = Math.min( 100, Math.max( 0, Math.round( nOpacity * 100 ) ) );

	oTexts.style.opacity = iOpacity / 100;
	oTexts.style.filter  = "alpha(opacity=" + iOpacity + ")";
}