求一个拖动层的例子
不要太复杂,越简单越好   
 要求如下 
  <div   id= "father ">  
  <div   id= "child1 ">  </div>          //该层可以响应拖动事件并拖动整个father层 
  <div   id= "child2 ">  </div>          //该层需要被带动一起拖动 
  </div>  
 实际就是要一个层窗口, 
 标题区域和内容区域,鼠标在内容区域不可以拖动,鼠标在标题区域可以拖动整个窗口,其中father代表了整个窗口,child1代表了标题区域,child2表示内容区域,     
 !在此基础上改就行   
  <script   language= "javascript ">     
 var   mouse_x,obj_x,mouse_y,obj_y 
 var   obj_moveable=false;      
 //开始拖动层 
 function   startDrag(obj){    
 mouse_x   =   event.clientX; 
 mouse_y   =   event.clientY; 
 obj_x=parseInt(obj.style.left); 
 obj_y=parseInt(obj.style.top); 
 obj.setCapture();    
 obj_moveable=true;    
 }      
 //拖动 
 function   drag(obj)   {    
 if(obj_moveable   &&   event.button==1)   {    
 obj.style.pixelLeft   =obj_x+(event.clientX-mouse_x)   ; 
 obj.style.pixelTop   =obj_y+(event.clientY-mouse_y)   ; 
 }    
 }      
 //停止拖动 
 function   stopDrag(obj){    
 obj.releaseCapture();    
 obj_moveable=false;    
 }    
  </script>    
  <div   id= "father "    
 onmousedown= "startDrag(this) "    
 onmouseup= "stopDrag(this) "    
 onmousemove= "drag(this) "   >  
  <div> 标题,鼠标在此可以拖动整个窗口 </div>  
  <div> 内容 </div>  
  </div>
------解决方案--------------------提供一个参考例子(将以下代码存成HTML看):   
  <html>  
  <head>  
  <title> DRAG the DIV </title>  
  <style>  
 *{font-size:12px} 
 .dragTable{ 
  font-size:12px; 
  border-top:1px solid #3366cc; 
  margin-bottom: 10px; 
  width:100%; 
  background-color:#FFFFFF; 
 } 
 .dragTR{ 
  cursor:move; 
  color:#7787cc; 
  background-color:#e5eef9; 
 } 
 td{vertical-align:top;} 
 #parentTable{ 
  border-collapse:collapse; 
  letter-spacing:25px; 
 } 
  </style>  
  <script defer>     
  var draged=false; 
  tdiv=null; 
 function dragStart(){ 
  ao=event.srcElement; 
  if((ao.tagName== "TD ")||(ao.tagName== "TR "))ao=ao.offsetParent; 
  else return; 
  draged=true; 
  tdiv=document.createElement( "div "); 
  tdiv.innerHTML=ao.outerHTML; 
  tdiv.style.display= "block "; 
  tdiv.style.position= "absolute "; 
  tdiv.style.filter= "alpha(opacity=70) "; 
  tdiv.style.cursor= "move "; 
  tdiv.style.width=ao.offsetWidth; 
  tdiv.style.height=ao.offsetHeight; 
  tdiv.style.top=getInfo(ao).top; 
  tdiv.style.left=getInfo(ao).left; 
  document.body.appendChild(tdiv); 
  lastX=event.clientX; 
  lastY=event.clientY; 
  lastLeft=tdiv.style.left; 
  lastTop=tdiv.style.top; 
  try{ 
   ao.dragDrop();  
  }catch(e){} 
 } 
 function draging(){//重要:判断MOUSE的位置 
  if(!draged)return; 
  var tX=event.clientX; 
  var tY=event.clientY; 
  tdiv.style.left=parseInt(lastLeft)+tX-lastX; 
  tdiv.style.top=parseInt(lastTop)+tY-lastY; 
  for(var i=0;i <parentTable.cells.length;i++){ 
   var parentCell=getInfo(parentTable.cells[i]); 
   if(tX> =parentCell.left&&tX <=parentCell.right&&tY> =parentCell.top&&tY <=parentCell.bottom){ 
    var subTables=parentTable.cell