判断Iframe是否加载完毕

var oFrm = document.getElementById('Iframe4');
oFrm.onload = oFrm.onreadystatechange = function () {
    if (this.readyState && this.readyState != 'complete') {
        //alert("加载中。。。");
    }
    else {
        var $listSearch = $('#Iframe4').contents().find('.listSearch');
        $listSearch.css("top", "30px");
    }
}