opacity渐变功能

function test(){
$("#popup").css("display","none");
$("#popup").css("opacity","1");
}
function timeshow1(){

$("#popup").animate({opacity: '0'},1000);
//$("#popup").animate({opacity: '1'},2000);
//setTimeout('test()', 2000);  
}
function  timeshow(){
$("#popup").css("display","");
setTimeout('timeshow1()', 4000); 
setTimeout('test()', 5000); 
}