div {
    -moz-user-select:none;
    -webkit-user-select:none;
    user-select:none;
}

// 先取到标签对象
if(document.all){
    //for ie
    obj.onselectstart= function(){return false;};
}else{
    obj.onmousedown= function(){return false;};
    obj.onmouseup= function(){return true;};
}
document.onselectstart = new Function(‘event.returnValue=false;‘);