function fDragging(obj, e, limit){ 
        if(!e) e=window.event; 
        obj=document.getElementById(obj);
        var x=parseInt(obj.style.left); 
        var y=parseInt(obj.style.top); 
         
        var x_=e.clientX-x; 
        var y_=e.clientY-y; 
         
        if(document.addEventListener){ 
            document.addEventListener("mousemove", inFmove, true); 
            document.addEventListener("mouseup", inFup, true); 
        } else if(document.attachEvent){ 
            document.attachEvent("onmousemove", inFmove); 
            document.attachEvent("onmouseup", inFup); 
        } 
         
        inFstop(e);     
        inFabort(e) 
         
        function inFmove(e){ 
            var evt; 
            if(!e)e=window.event; 
             
            if(limit){ 
                var op=obj.parentNode; 
                var opX=parseInt(op.style.left); 
                var opY=parseInt(op.style.top); 
                 
                if((e.clientX-x_)<0) return false; 
                else if((e.clientX-x_+obj.offsetWidth+opX)>(opX+op.offsetWidth)) return false; 
                 
                if(e.clientY-y_<0) return false; 
                else if((e.clientY-y_+obj.offsetHeight+opY)>(opY+op.offsetHeight)) return false; 

            } 
             
            obj.style.left=e.clientX-x_+"px"; 
            obj.style.top=e.clientY-y_+"px"; 
             
            inFstop(e); 
        }
        function inFup(e){ 
            var evt; 
            if(!e)e=window.event; 
             
            if(document.removeEventListener){ 
                document.removeEventListener("mousemove", inFmove, true); 
                document.removeEventListener("mouseup", inFup, true); 
            } else if(document.detachEvent){ 
                document.detachEvent("onmousemove", inFmove); 
                document.detachEvent("onmouseup", inFup); 
            } 
             
            inFstop(e); 
        }
  
        function inFstop(e){ 
            if(e.stopPropagation) return e.stopPropagation(); 
            else return e.cancelBubble=true;             
        }
        function inFabort(e){ 
            if(e.preventDefault) return e.preventDefault(); 
            else return e.returnValue=false; 
        } 
    }