function getScrollY() {
scrOfY = 0;
if( typeof( window.pageYOffset ) == "number" ) {
scrOfY = window.pageYOffset;
} else if( document.body && ( document.body.scrollLeft || document.body.scrollTop ) ) {
scrOfY = document.body.scrollTop;
} else if( document.documentElement && ( document.documentElement.scrollLeft || document.documentElement.scrollTop ) ) {
scrOfY = document.documentElement.scrollTop;
}
return scrOfY;
}
jQuery(function($){
var upprev_closed = false;
var upprev_hidden = true;
$(window).scroll(function() {
var lastScreen = getScrollY() + $(window).height() < $(document).height() * 0.5 ? false : true;
if (lastScreen && !upprev_closed) {
$("#upprev_box").stop().animate({right:"0px"});
upprev_hidden = false;
}
else if (upprev_closed && getScrollY() == 0) {
upprev_closed = false;
}
else if (!upprev_hidden) {
upprev_hidden = true;
$("#upprev_box").stop().animate({right:"-400px"});
}
});
$("#upprev_close").click(function() {
$("#upprev_box").stop().animate({right:"-400px"});
upprev_closed = true;
upprev_hidden = true;
});
});