function getBrowserCodeName()
{
	var name = null;
	
	if ( document.getElementById && !document.all )
	{
		name = 'NS6';
	}
	else if ( document.all )
	{
		name = 'IE';
	}
	else if ( navigator.appName == 'Netscape' && navigator.appVersion.charAt( 0 ) == '4' )
	{
		name = 'NS';
	}
	else if ( navigator.userAgent.indexOf( 'Mac' ) != -1 )
	{
		name = 'MAC';
	}

	if (navigator.userAgent.match('Chrome')) {
		name = 'NS6';
	}

	if (navigator.userAgent.match('Firefox')) {
		name = 'FF';
	}

	if (navigator.userAgent.match('Safari')) {
		name = 'NS6';
	}

	return name;
}

function get_xy(obj){
	var mon_tab = new Array();
	var x = obj.offsetLeft;
	var y = obj.offsetTop;

	while (obj = obj.offsetParent){
		x += obj.offsetLeft;
		y += obj.offsetTop;
	}

	mon_tab = [x,y];
	return mon_tab;
}

var start_y = get_xy(document.getElementById('scroll_div'))[1]-20;

window.onscroll=function(){
	var my_div = document.getElementById('scroll_div');

	my_clientHeight = document.documentElement.clientHeight;
	my_clientWidth = document.documentElement.clientWidth;
	my_scrollTop = document.documentElement.scrollTop;
	if(my_clientHeight==0){
		my_clientHeight = document.body.clientHeight;
		my_clientWidth = document.body.clientWidth;
	}
	if(my_scrollTop==0){
		my_scrollTop = document.body.scrollTop;
	}

	if(my_scrollTop>start_y){
		my_div.style.top = my_scrollTop-start_y +'px';
	}
	
	if(my_scrollTop<start_y && my_div.style.top!=''){
		my_div.style.top = '0px';
	}
}