弹出z-index:1的div 和 消失, 兼容ff和ie

//鼠标点击空白处, 弹出的z-index:1的div消失, 兼容ff和ie
$(document).ready( function(){
        $(document).click( function(e){
                 var t;
                 if(document.all) t = document.elementFromPoint(event.x,event.y).tagName;
                 else t = e.target.tagName;
                 if(t=='BODY'||t=='DIV'||t=='TD'||t=='IMG')
                        $('#pop').hide();
        });
});

//鼠标点击链接, 在点中的链接处弹出z-index:1的div, 兼容ff和ie
function show_pop(e){
        $('#popcontent').html('加载中...');
         var x,y;
         if(document.all){
                x = e.x;
                y = e.y;
                $('#pop').css('top',document.body.scrollTop+y+20);
        } else{
                x = e.pageX;
                y = e.pageY;
                $('#pop').css('top',document.documentElement.scrollTop+y+20);
        }
        $('#pop').css('left',x-130);
        $('#pop').show();
}