/// <summary>
/// 在某个对象上显示一个遮罩层并在遮罩的中间显示一个loading-box（不支持IE6下对SELECT的遮罩）
/// usage:$("#divContainer").mask("tip message","mask Layer id","loading Box id");
/// @tip message    可选项，默认值：loading
/// @mask layer id  可选项，默认值：maskLayer
/// @loading box id 可选项，默认值：loadingBox
/// </summary>
$.fn.extend({
    mask:function(msg,mlid,lbid){
        mlid = mlid || "maskLayer";
        lbid = lbid || "loadingBox";
        msg = msg || "loading";
        $.nomask(mlid,lbid);
        var os = this.offset();
        $('<div id="' + mlid + '"></div>').appendTo('body');
        $("#"+mlid).css({position:'absolute',left:os.left,top:os.top,width:this.width(),height:this.height(),backgroundColor:'#000000'}).css('filter','alpha(opacity="30")').css('-moz-opacity','0.3');
        $('<div class="loading-box" id="' + lbid + '"></div>').html("<div>" + msg + "</div>").css("position","absolute").appendTo("body");
        $("#"+lbid).css({left:$("#"+mlid).offset().left+($("#"+mlid).width()-$("#"+lbid).width())/2,top:$("#"+mlid).offset().top+($("#"+mlid).height()-$("#"+lbid).height())/2});
    }
});
/// <summary>
/// 移除显示的遮罩
/// usage:$.nomask("mask Layer id","loading Box id");
/// @mask layer id  可选项，默认值：maskLayer
/// @loading box id 可选项，默认值：loadingBox
/// </summary>
$.extend({
    nomask:function(mlid,lbid){
        mlid = mlid || "maskLayer";
        lbid = lbid || "loadingBox";
        if ( $("#"+mlid) )
            $("#"+mlid).remove();
        if ( $("#"+lbid) )
            $("#"+lbid).remove();
    }
});