function slideThumb(dir){
	var thumbPos = [15,161,299,437,577];
	var sliderPos = [15,-393,-658,-895,-900];
	
	//get position of slider thumb
	var x = Element.getStyle('sliderThumb', 'left' );
	//strip 'px' and return an integer for thumb position
	var x = parseFloat(x);
	
	
	function changeStyle(sli,scr){
		animateSlider(sli); 
		animateScroller(scr);
	}
	
	// for error checking
	function getVals(){
		var slider = Element.getStyle('scrollList', 'left' );
		var thumb = Element.getStyle('sliderThumb', 'left' );
		$('debug2').innerHTML='dir:' + dir + ' x:'+ x + ' slider x:' + slider + ' new x:' + thumb;
	}
	if(dir=="R"){
		if(x < 20){
			changeStyle(thumbPos[0],sliderPos[0]);
		} else if (x < 161){
			changeStyle(thumbPos[1],sliderPos[1]);
		} else if (x < 299){
			changeStyle(thumbPos[2],sliderPos[2]);
		} else if (x < 437){
			changeStyle(thumbPos[3],sliderPos[3]);
		} else if (x < 577){
			changeStyle(thumbPos[4],sliderPos[4]);
		}	
	}
	
	if(dir=="L"){
		if(x > 20 && x < 162){
			changeStyle(thumbPos[0],sliderPos[0]);
		} else if (x > 161 && x < 300){
			changeStyle(thumbPos[1],sliderPos[1]);
		} else if (x > 299 && x < 438){
			changeStyle(thumbPos[2],sliderPos[2]);
		} else if (x > 437 && x < 578){
			changeStyle(thumbPos[3],sliderPos[3]);
		} else if (x > 577){
			changeStyle(thumbPos[4],sliderPos[4]);
		}
	}
}