js获取宽高

var wh = {};

"fo_dlg_3 fo_dlg_4".replace(/[^ ]+/g,function(a){

var elem = document.getElementById(a);

        wh[a] = {};

'Width Height'.replace(/[^ ]+/g, function(i){

wh[a][i] = elem['offset' + i] || elem['client' + i];

});

});

console.log(wh);