图片滚动问题（急）

Question

我用的是下面的js
      <script>
                                                            var speed_zj = 30//速度数值越大速度越慢
                                                            demo2_zj.innerHTML = demo1_zj.innerHTML
                                                            function Marquee_zj() {
                                                                if (demo2_zj.offsetWidth - demo_zj.scrollLeft <= 0)
                                                                    demo_zj.scrollLeft -= demo1_zj.offsetWidth
                                                                else {
                                                                    demo_zj.scrollLeft++
                                                                }
                                                            }
                                                            var MyMar_zj = setInterval(Marquee_zj, speed_zj)
                                                            demo_zj.onmouseover = function() { clearInterval(MyMar_zj) }
                                                            demo_zj.onmouseout = function() { MyMar_zj = setInterval(Marquee_zj, speed_zj) }
                                                        </script>在IE7里正常，可是在火狐，ie6中就不会滚动，而且页面被撑的很大，请帮帮忙，很急