var fl_lastScrollX = 0;
var fl_lastScrollY = 0;
var fl_objlayer = null;
function init_follow_layer(obj, interval) {
	// IE: document.all.obj
	// NS: document.obj
	if ((typeof(obj) != 'undefined') && (obj != null)) {
		var NS = (document.layers) ? 1 : 0;
		var IE = (document.all) ? 1: 0;
		if (NS || IE) {
			fl_objlayer = obj;
			var action = window.setInterval("fl_heartBeat()", interval);
		}
	}
}
function fl_heartBeat() {
	var NS = (document.layers) ? 1 : 0;
	var IE = (document.all) ? 1: 0;
	var chg_dlt = .2;		// 0 to 1
	if(IE) { 
		diffY = document.body.scrollTop; 
		diffX = 0; 
	}
	else if(NS) { 
		diffY = self.pageYOffset;
		diffX = self.pageXOffset; 
	}
	if(diffY != fl_lastScrollY) {
		percent = chg_dlt * (diffY - fl_lastScrollY);
		if (percent > 0) percent = Math.ceil(percent);
		else percent = Math.floor(percent);
		if (IE) fl_objlayer.style.pixelTop += percent;
		if (NS) fl_objlayer.top += percent; 
		fl_lastScrollY = fl_lastScrollY + percent;
	}
	if(diffX != fl_lastScrollX) {
		percent = chg_dlt * (diffX - fl_lastScrollX);
		if (percent > 0) percent = Math.ceil(percent);
		else percent = Math.floor(percent);
		if (IE) fl_objlayer.style.pixelLeft += percent;
		if (NS) fl_objlayer.top += percent;
		fl_lastScrollY = fl_lastScrollY + percent;
	}	
}