first jQuery

很实用的 javascript 库

$(
function(){
    var i = 0 ;
    var bkc = ["red","blue","green","gray"] ;
    $("input").click(function(){
        if(i==0)
            $("img").fadeOut("slow");
        else if(i==bkc.length/2)
            $("img").fadeIn("slow");
        $("body").css({"background-color":bkc[i]}) ;
        if(++i>=bkc.length)
            i = 0 ;
        $(this).val("Next "+bkc[i]) ;
    })
});