var xpos = 100; //起始定位：x轴位置（居左像素）
var ypos = 100;  //起始定位：y轴位置（居上像素）
var step = 1; //每次移动像素
var delay = 80; //每移1次setp所需时间（单位毫秒，1000毫秒=1秒）
var height = 0;
var hoffset = 0;
var woffset = 0;
var yon = 0;
var xon = 0;
var pause = true;
var interval;
var obj=window.document.getelementbyid("img123"); //获取div图层对象
obj.style.top = ypos + "px";
var $obj2;
$(function() {
    $obj2 = $("#img123");
    $obj2.mouseenter(function() {
                clearinterval(interval);
        pause = false;
    });
    $obj2.mouseout(function() {
        interval = setinterval('changepos()',delay);
        pause = true; 
    });
});

function changepos(){
    width = window.innerwidth == 0 ? (document.documentelement.clientwidth == 0 ? document.body.clientwidth : document.documentelement.clientwidth) : window.innerwidth;
    height = window.innerheight == 0 ? (document.documentelement.clientheight == 0 ? document.body.clientheight : document.documentelement.clientheight) : window.innerheight;
    woffset = obj.offsetwidth;
    hoffset = obj.offsetheight;
    scrollleft = document.documentelement.scrollleft == 0 ? document.body.scrollleft : document.documentelement.scrollleft;
    scrolltop = document.documentelement.scrolltop == 0 ? document.body.scrolltop : document.documentelement.scrolltop;
    obj.style.left = xpos + scrollleft + "px";
    obj.style.top = ypos + scrolltop + "px";
    if (yon) {ypos = ypos + step;}
    else {ypos = ypos - step;}
    if (ypos < 0) {yon = 1;ypos = 0;}
    if (ypos >= (height - hoffset)) {yon = 0;ypos = (height - hoffset);}
    if (xon) {xpos = xpos + step;}
    else {xpos = xpos - step;}
    if (xpos < 0) {xon = 1;xpos = 0;}
    if (xpos >= (width - woffset)) {xon = 0;xpos = (width - woffset);}
}
function start(){
    obj.visibility = "visible";
    interval = setinterval('changepos()', delay);
}
function pause_resume(){
    if(pause){
        clearinterval(interval);
        pause = false;
    }else{
        interval = setinterval('changepos()',delay);
        pause = true; 
    }
}
start();
$(function() {
    $("#a").click(function() {
        var b = $("#a").parent();
        $(b).remove();
    })
})