使用 setTimeout 运行的停止函数

ham*_*mze 2 javascript

我想停止使用 setTimeout 运行的函数,并且不显示跟随鼠标的图像。我想通过单击按钮来做到这一点,怎么做?我的代码:

<html xmlns="http://www.w3.org/1999/xhtml">
<head id="Head1" runat="server">
<title></title>
<script type="text/javascript">
    var trailimage = ["test.gif", 100, 99];
    var offsetfrommouse = [-25, -25];
    var displayduration = 0;
    function truebody() {
        return (!window.opera && document.compatMode && document.compatMode != "BackCompat") ? document.documentElement : document.body;
    }
    function hidetrail() {
        var x = document.getElementById("trailimageid").style;
        x.visibility = "hidden";
        document.onmousemove = "";
    }
    function followmouse(e) {
        var xcoord = offsetfrommouse[0];
        var ycoord = offsetfrommouse[1];
        if (typeof e != "undefined") {
            xcoord += e.pageX;
            ycoord += e.pageY;
        }
        else if (typeof window.event != "undefined") {
            xcoord += truebody().scrollLeft + event.clientX;
            ycoord += truebody().scrollTop + event.clientY;
        }
        var x = document.getElementById("trailimageid").style;
        x.left = xcoord + "px";
        x.top = ycoord + "px";            
    }

        alert("obj_selected = true");
        document.onmousemove = followmouse;
        if (displayduration > 0)
            setTimeout("hidetrail()", displayduration * 1000);

</script>
</head>
<body>
<form id="form1" runat="server">

    <img alt="" id="trailimageid" src="Pictures/sides/sides-not-clicked.gif" border="0" style="position: absolute; visibility: visible; left: 0px;
    top: 0px; width: 50px; height: 50px"/>

</form>
 </body>
</html>
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