$(document).ready(function(){
	$(window).scroll(function(){
		if($(this).scrollTop() >
		//$(window).height()*0.3){
		100) {
			$(".mind-global-header_arrow-down").css({"opacity" : "0"});
		} else {
			$(".mind-global-header_arrow-down").css({"opacity" : "0.4"});
		}
	});
});