/** 
功能：拖动对象，并置当前对象为最高层 
作者：feifengxlq《许立强》feifengxlq@hotmail.com 
时间: 2006-10-24 
演示： 
*/ 
var move_obj_x0=0,move_obj_y0=0,move_obj_x1=0,move_obj_y1=0;//(x0,y0)为开始拖动时鼠标的位置(x1,y1)为开始拖动时对象的位置 
var obj_moveable=false; 

//开始拖动; 
function startDrag(obj,id) 
{ 
    if(event.button==1) 
    { 
        obj.setCapture(); 
        win=document.getElementById(id) 
        move_obj_x0 = event.clientX; 
        move_obj_y0 = event.clientY; 
        move_obj_x1 = parseInt(win.style.left); 
        move_obj_y1 = parseInt(win.style.top); 
        obj_moveable = true; 
    } 
} 
//拖动; 
function drag(id) 
{ 
    if(obj_moveable) 
    { 
        win=document.getElementById(id) 
        win.style.left = (move_obj_x1 + event.clientX - move_obj_x0>0)?move_obj_x1 + event.clientX - move_obj_x0:0; 
        win.style.top = (move_obj_y1 + event.clientY - move_obj_y0>0)?move_obj_y1 + event.clientY - move_obj_y0:0; 
    } 
} 
//停止拖动; 
function stopDrag(obj,id) 
{ 
    if(obj_moveable) 
    { 
        obj.releaseCapture(); 
        obj_moveable = false; 
    } 
}