2个JS脚本有冲突,页面执行任何一个都是正常的,把两个放一起就报错

请高手看下什么原因
一个是下拉菜单的JSvar timeout = 500;
var closetimer = 0;
var ddmenuitem = 0;
function jsddm_open()
{ jsddm_canceltimer();
jsddm_close();
ddmenuitem = $(this).find('ul').eq(0).css('visibility', 'visible');}
function jsddm_close()
{ if(ddmenuitem) ddmenuitem.css('visibility', 'hidden');}function jsddm_timer()
{ closetimer = window.setTimeout(jsddm_close, timeout);}function jsddm_canceltimer()
{ if(closetimer)
{ window.clearTimeout(closetimer);
closetimer = null;}}
$(document).ready(function()
{ $('#nav > li').bind('mouseover', jsddm_open);
$('#nav > li').bind('mouseout',  jsddm_timer);});
document.onclick = jsddm_close;另一个是图片切换的JS// JavaScript Document  资讯幻灯片 CSSfunction $(id) { return document.getElementById(id); }function addLoadEvent(func){
var oldonload = window.onload;
if (typeof window.onload != 'function') {
window.onload = func;
} else {
window.onload = function(){
oldonload();
func();
}
}
}function moveElement(elementID,final_x,final_y,interval) {
  if (!document.getElementById) return false;
  if (!document.getElementById(elementID)) return false;
  var elem = document.getElementById(elementID);
  if (elem.movement) {
    clearTimeout(elem.movement);
  }
  if (!elem.style.left) {
    elem.style.left = "0px";
  }
  if (!elem.style.top) {
    elem.style.top = "0px";
  }
  var xpos = parseInt(elem.style.left);
  var ypos = parseInt(elem.style.top);
  if (xpos == final_x && ypos == final_y) {
return true;
  }
  if (xpos < final_x) {
    var dist = Math.ceil((final_x - xpos)/10);
    xpos = xpos + dist;
  }
  if (xpos > final_x) {
    var dist = Math.ceil((xpos - final_x)/10);
    xpos = xpos - dist;
  }
  if (ypos < final_y) {
    var dist = Math.ceil((final_y - ypos)/10);
    ypos = ypos + dist;
  }
  if (ypos > final_y) {
    var dist = Math.ceil((ypos - final_y)/10);
    ypos = ypos - dist;
  }
  elem.style.left = xpos + "px";
  elem.style.top = ypos + "px";
  var repeat = "moveElement('"+elementID+"',"+final_x+","+final_y+","+interval+")";
  elem.movement = setTimeout(repeat,interval);
}function classNormal(iFocusBtnID,iFocusTxID){
var iFocusBtns= $(iFocusBtnID).getElementsByTagName('li');
var iFocusTxs = $(iFocusTxID).getElementsByTagName('li');
for(var i=0; i<iFocusBtns.length; i++) {
iFocusBtns[i].className='normal';
iFocusTxs[i].className='normal';
}
}function classCurrent(iFocusBtnID,iFocusTxID,n){
var iFocusBtns= $(iFocusBtnID).getElementsByTagName('li');
var iFocusTxs = $(iFocusTxID).getElementsByTagName('li');
iFocusBtns[n].className='current';
iFocusTxs[n].className='current';
}function iFocusChange() {
if(!$('ifocus')) return false;
$('ifocus').onmouseover = function(){atuokey = true};
$('ifocus').onmouseout = function(){atuokey = false};
var iFocusBtns = $('ifocus_btn').getElementsByTagName('li');
var listLength = iFocusBtns.length;
iFocusBtns[0].onmouseover = function() {
moveElement('ifocus_piclist',0,0,5);
classNormal('ifocus_btn','ifocus_tx');
classCurrent('ifocus_btn','ifocus_tx',0);
}
if (listLength>=2) {
iFocusBtns[1].onmouseover = function() {
moveElement('ifocus_piclist',0,-447,5);
classNormal('ifocus_btn','ifocus_tx');
classCurrent('ifocus_btn','ifocus_tx',1);
}
}
if (listLength>=3) {
iFocusBtns[2].onmouseover = function() {
moveElement('ifocus_piclist',0,-894,5);
classNormal('ifocus_btn','ifocus_tx');
classCurrent('ifocus_btn','ifocus_tx',2);
}
}
if (listLength>=4) {
iFocusBtns[3].onmouseover = function() {
moveElement('ifocus_piclist',0,-1341,5);
classNormal('ifocus_btn','ifocus_tx');
classCurrent('ifocus_btn','ifocus_tx',3);
}
}
if (listLength>=5) {
iFocusBtns[4].onmouseover = function() {
moveElement('ifocus_piclist',0,-1788,5);
classNormal('ifocus_btn','ifocus_tx');
classCurrent('ifocus_btn','ifocus_tx',4);
}
}
}setInterval('autoiFocus()',5000);
var atuokey = false;
function autoiFocus() {
if(!$('ifocus')) return false;
if(atuokey) return false;
var focusBtnList = $('ifocus_btn').getElementsByTagName('li');
var listLength = focusBtnList.length;
for(var i=0; i<listLength; i++) {
if (focusBtnList[i].className == 'current') var currentNum = i;
}
if (currentNum==0&&listLength!=1 ){
moveElement('ifocus_piclist',0,-447,5);
classNormal('ifocus_btn','ifocus_tx');
classCurrent('ifocus_btn','ifocus_tx',1);
}
if (currentNum==1&&listLength!=2 ){
moveElement('ifocus_piclist',0,-894,5);
classNormal('ifocus_btn','ifocus_tx');
classCurrent('ifocus_btn','ifocus_tx',2);
}
if (currentNum==2&&listLength!=3 ){
moveElement('ifocus_piclist',0,-1341,5);
classNormal('ifocus_btn','ifocus_tx');
classCurrent('ifocus_btn','ifocus_tx',3);
}
if (currentNum==3&&listLength!=4 ){
moveElement('ifocus_piclist',0,-1788,5);
classNormal('ifocus_btn','ifocus_tx');
classCurrent('ifocus_btn','ifocus_tx',4);
}
if (currentNum==4 ){
moveElement('ifocus_piclist',0,0,5);
classNormal('ifocus_btn','ifocus_tx');
classCurrent('ifocus_btn','ifocus_tx',0);
}
if (currentNum==1&&listLength==2 ){
moveElement('ifocus_piclist',0,0,5);
classNormal('ifocus_btn','ifocus_tx');
classCurrent('ifocus_btn','ifocus_tx',0);
}
if (currentNum==2&&listLength==3 ){
moveElement('ifocus_piclist',0,0,5);
classNormal('ifocus_btn','ifocus_tx');
classCurrent('ifocus_btn','ifocus_tx',0);
}
if (currentNum==3&&listLength==4 ){
moveElement('ifocus_piclist',0,0,5);
classNormal('ifocus_btn','ifocus_tx');
classCurrent('ifocus_btn','ifocus_tx',0);
}
}
addLoadEvent(iFocusChange);
两个放一起就报错,提示错误行在第一个JS里
消息: 'null' 为空或不是对象
{ $('#nav > li').bind('mouseover', jsddm_open);