请懂flash相关脚本的大侠帮忙分析下这段代码 最好写出每一行的功能作用（尤其是鼠标控制小球的代码部分）

Question

var mouseIsDowning:Boolean
var speed:Number =10
var sp:Sprite=new Sprite()
sp.x=100
sp.y=50
this.addChild(sp)
drawCircle(sp.graphics )
sp.addEventListener (Event.ENTER_FRAME ,loop)

stage.frameRate=30
stage.addEventListener (MouseEvent.MOUSE_DOWN ,checkFunc)
stage.addEventListener (MouseEvent.MOUSE_UP ,checkFunc)
function loop(e:Event)
{
e.target.y+=mouseIsDowning?-speed:speed
}
function checkFunc(e:MouseEvent)
{
if(e.type==MouseEvent.MOUSE_DOWN )
{
mouseIsDowning=true
}
else if(e.type==MouseEvent.MOUSE_UP )
{
mouseIsDowning=false
}
}
function drawCircle(g:Graphics )
{
g.lineStyle(30,0xFF9900,1)
g.lineTo(0.5,0.5)
}

Answer 1

var mouseIsDowning:Boolean
var speed:Number =10

//建立一个容器，可以理解成影片剪辑
var sp:Sprite=new Sprite()
sp.x=100
sp.y=50
this.addChild(sp)

//在容器里绘制一条线
drawCircle(sp.graphics )
sp.addEventListener (Event.ENTER_FRAME ,loop)

stage.frameRate=30
stage.addEventListener (MouseEvent.MOUSE_DOWN ,checkFunc)
stage.addEventListener (MouseEvent.MOUSE_UP ,checkFunc)
function loop(e:Event)
{
//让画了线的容器向左移动 按下鼠标时向右移动
e.target.y+=mouseIsDowning?-speed:speed
}

//鼠标事件处理函数
function checkFunc(e:MouseEvent)
{
//根据鼠标按下还是松开 设置变量 mouseIsDowning的值为true/false
if(e.type==MouseEvent.MOUSE_DOWN )
{
mouseIsDowning=true
}
else if(e.type==MouseEvent.MOUSE_UP )
{
mouseIsDowning=false
}
}

//画线的函数
function drawCircle(g:Graphics )
{
g.lineStyle(30,0xFF9900,1)
g.lineTo(0.5,0.5)
}

Answer 2

看起来像是自动输账号密码的，但是好像不完整

追问

这是个点击鼠标 小球不会下降的代码

Answer 3

天书啊