function initiateScroller() {
    if(document.getElementById("cat_hl_172927")) {
        
        var totalObjs = $("#cat_hl_172927 span.odd, #cat_hl_172927 span.even").length;
        if(totalObjs <= 4)
            $("#scroller_buttons").hide();

        swapButtonsDisplay();
        
        if(document.getElementById("scroll_back")) {
            $("#scroll_back").click(
                function() {
	        		try {
				            var marginLeft = getPixelValue($("#cat_hl_172927").css("margin-left"));
				            if(marginLeft < 0) {
					            marginLeft = marginLeft + 640;
					            $("#cat_hl_172927").animate({marginLeft: marginLeft + "px"}, 250, "swing", swapButtonsDisplay);
				            }
            			}
    			    catch(ex) {}
			        finally {return false;}
	            }
            ); // click concludes
        } // if concludes
        
        
        if(document.getElementById("scroll_forward")) {
            $("#scroll_forward").click(
                function() {
	        		try {
				            var marginLeft = getPixelValue($("#cat_hl_172927").css("margin-left"));
				            var maxMarginLeft = (0 - ((totalObjs * 160) - (4 * 160)));
				            if(totalObjs <= 4 || (marginLeft > maxMarginLeft)) {
					            marginLeft = marginLeft - 640;
					            $("#cat_hl_172927").animate({marginLeft: marginLeft + "px"}, 250, "swing", swapButtonsDisplay);
				            }
            			}
    			    catch(ex) {}
			        finally {return false;}
	            }
            ); // click concludes
        } // if concludes 
   }   
   
   function getPixelValue(value) {
		var val = value;
		if(val == "auto")
			val= "0";
		val = parseInt(val.replace("px",""));
		return val;
	}; // getPixelValue concludes
	
	
	function swapButtonsDisplay() {
	
        var marginLeft = getPixelValue($("#cat_hl_172927").css("margin-left"));
        var totalObjs = $("#cat_hl_172927 span.odd, #cat_hl_172927 span.even").length;
        var totalPossibleScrolls = (Math.ceil(totalObjs / 4) - 1);
        var maxPossibleLeftMargin = (-1) * (640 * totalPossibleScrolls);
        var currentlyItIs = getPixelValue($("#cat_hl_172927").css("margin-left"));

        // cannot go any more forward
        if(currentlyItIs == maxPossibleLeftMargin) {
            $("#scroll_forward").removeClass();
            $("#scroll_forward").addClass("no_more_forward");
            $("#scroll_back").removeClass();
            $("#scroll_back").addClass("back");
        }
        // can go forward, both buttons to appear here
        else if(currentlyItIs > maxPossibleLeftMargin && currentlyItIs != 0) {
            $("#scroll_back").removeClass();
            $("#scroll_back").addClass("back");
            $("#scroll_forward").removeClass();
            $("#scroll_forward").addClass("forward");
        }
        else if (currentlyItIs == 0) {
            $("#scroll_back").removeClass();
            $("#scroll_back").addClass("no_more_back");
            $("#scroll_forward").removeClass();
            $("#scroll_forward").addClass("forward");
        }
	}; // swapButtonsDisplay concludes
	
};


$(document).ready(initiateScroller);