php 输出js问题

 下面是当鼠标放在图片上有个层显示内容的js
document.write("<div id='pup' style='position:absolute; border: 1px solid gray;z-index:10;color:#FFFFFF;line-height=16px;background: #FFFFE1; width:149px;overflow: visible;visibility: hidden;font-size:12px;padding:2px;text-align: left'></div>")var displayObj = null;var a=0;
function showpup(e,str){
showpupCommon(null,e,str);
}
function showpupCommon(divWidth,e,str)
{
var disObj = null;
if(displayObj==str)return;
var left=-21,top=e.height+5;
var x,y;
while (e.offsetParent){
left += e.offsetLeft;
top  += e.offsetTop;
e     = e.offsetParent;
} left += e.offsetLeft;
top  += e.offsetTop;
x = left;
y = top;
if (document.layers){
disObj = document.layers['pup'];
        disObj.left = x;
        disObj.top = y;
    }
    else if (document.all){
disObj = document.all['pup'];
disObj.style.left=x;
        disObj.style.top=y;
    }
    else if (document.getElementById){
        disObj = document.getElementById('pup');
disObj.style.left=x+"px";
        disObj.style.top=y+"px";
    } disObj.style.visibility="visible";
if(divWidth!=null && divWidth!=""){
disObj.style.width=divWidth+"px";
}else{
disObj.style.width="143px";
}
disObj.innerHTML=str;
displayObj = str;
a=0;
checkBrowserForVersion4();
}function showpupindex(imgObj,val){
showpupCommon(264,imgObj,val);
}function hidepup()
{
  pup.style.innerHTML=""
  pup.style.visibility="hidden";
  displayObj = null;
}
function  hidepupTip(){
var div = document.all.pup;
var div1 = document.all.searchInput;
if(div.componentFromPoint(event.clientX,event.clientY)=="outside" && div1.componentFromPoint(event.clientX,event.clientY)=="outside")
{
div.style.visibility='hidden'
}
}function checkBrowserForVersion4(){
var x=navigator.appVersion;
y=x.substring(0,4);
if(y>=4) Effect();
}var isNav=(navigator.appName.indexOf("Netscape")!=-1);
var colors=new Array ("FFFFFF","FFFFFF","FFFFFF","FFFFFF","FFFFFF","FFFFFF","FFFFFF","F9F9F9","F1F1F1","E9E9E9","E1E1E1","D9D9D9","D1D1D1","C9C9C9","C1C1C1","B9B9B9","B1B1B1","A9A9A9","A1A1A1","999999","919191","898989","818181","797979","717171","696969","616161","595959","515151","494949","414141","393939","313131","292929","212121","191919","111111","090909","000000");function Effect(){
color=colors[a];
pup.style.color = color;

if(a<colors.length){
a++;
xx=setTimeout("Effect()",30);
}
}
//////////////////////////
我的php代码
$js="showup(this,'".$jobstr."')";   <IMG 
                  onmousemove="<? echo $js ?>" 
                  onmouseout=hidepup() height=35 
                  src="upload/company/<? echo $advance_data["pic_path"]?>" width=139 
                border=0>
$jobstr 为数据库循环获得的字符串
现在提示缺少对象错误，不知哪里问题，
查看源码好像也没有什么错误