以下代码在IE8下运行通过，在IE9中出错：

思路分析：
第一步：兼容IE9，firefox，Opera，Safari等浏览器；

第二步：兼容IE6-8：由于ie6-8 不能修改iframe的name属性

综合解决办法:

function ajaxpost(formid, showid, waitid, showidclass, submitbtn, recall) {
    var waitid = typeof waitid == \'undefined\' || waitid === null ? showid : (waitid !== \'\' ? waitid : \'\');
    var showidclass = !showidclass ? \'\' : showidclass;
    var ajaxframeid = \'ajaxframe\';
    var ajaxframe = $(ajaxframeid);
    var formtarget = $(formid).target;

    var handleResult = function() {
        var s = \'\';
        var evaled = false;

        showloading(\'none\');
        try {
            s = $(ajaxframeid).contentWindow.document.XMLDocument.text;
        } catch (e) {
            try {
                s = $(ajaxframeid).contentWindow.document.documentElement.firstChild.wholeText;
            } catch (e) {
                try {
                    s = $(ajaxframeid).contentWindow.document.documentElement.firstChild.nodeValue;
                } catch (e) {
                    s = \'内部错误，无法显示此内容\';
                }
            }
        }

        if (s != \'\' && s.indexOf(\'ajaxerror\') != -1) {
            evalscript(s);
            evaled = true;
        }
        if (showidclass) {
            $(showid).className = showidclass;
            if (submitbtn) {
                submitbtn.disabled = false;
            }
        }
        if (!evaled && (typeof ajaxerror == \'undefined\' || !ajaxerror)) {
            ajaxinnerhtml($(showid), s);
        }
        ajaxerror = null;
        if ($(formid)) $(formid).target = formtarget;
        if (typeof recall == \'function\') {
            recall();
        } else {
            eval(recall);
        }
        if (!evaled) evalscript(s);
        ajaxframe.loading = 0;
        $(\'append_parent\').removeChild(ajaxframe);
    };
    if (!ajaxframe) {
        try {
            ajaxframe = document.createElement(\'<iframe name=\"\' + ajaxframeid + \'\" id=\"\' + ajaxframeid + \'\"></iframe>\');
        } catch (e) {
            ajaxframe = document.createElement(\'iframe\');
            ajaxframe.name = ajaxframeid;
            ajaxframe.id = ajaxframeid;
        }
        ajaxframe.style.display = \'none\';
        ajaxframe.loading = 1;
        $(\'append_parent\').appendChild(ajaxframe);
    } else if (ajaxframe.loading) {
        return false;
    }

    _attachEvent(ajaxframe, \'load\', handleResult);

    showloading();
    $(formid).target = ajaxframeid;
    $(formid).action += \'&inajax=1\';
    $(formid).submit();
    return false;
}