function  cc(tt,div)  
{  
   var  daps    =  document.getElementById(div).style;  
   var  ttop    =  tt.offsetTop;          //TT控件的定位点高
   var  thei    =  tt.clientHeight;    //TT控件本身的高  
   var  tleft  =  tt.offsetLeft;        //TT控件的定位点
   var  ttyp    =  tt.type;                    //TT控件的类型
   tt.offsetParent.style.backgroundColor="#9EA6AB";
   while  (tt  =  tt.offsetParent){ttop+=tt.offsetTop;  tleft+=tt.offsetLeft;}  
   tmp    =  (ttyp=="image")?  ttop+thei  :  ttop+thei;  //层的  Y  坐标  
   daps.top = tmp +"px";
   daps.left  =  tleft+"px" ;    //层的  X  坐标   
   daps.display  =  "block";    //层显示 
   
   var sub_shadow = document.getElementById("sub_shadow").style;
   
   sub_shadow.height =    document.getElementById(div).scrollHeight+"px";
   sub_shadow.top = (tmp+5) +"px";
   sub_shadow.left  =  (tleft+5)+"px" ;    //层的  X  坐标  
   sub_shadow.display  =  "block";  
   sub_shadow.width = document.getElementById(div).scrollWidth+"px"
}  

function disappear(tt){
   //document.getElementById('sub_home').style.display  =  "none";    
   document.getElementById('sub_services').style.display  =  "none";    
   document.getElementById('sub_contact_us').style.display  =  "none"; 
   document.getElementById("sub_shadow").style.display  =  "none"; 
   if(tt != ''){
   	tt.offsetParent.style.backgroundColor="";
   }
}

function show(tt){
	tt.style.display = 'block';
    document.getElementById("sub_shadow").style.display  =  "block";
}