搜索后重新加载页面上拉刷新无反应

初始加载上拉正常，表单中增加选择条件提交需要重新加载页面，上拉无反应，贴代码

function pullupRefresh() {  
    if (first) {  
        alert('第一次');  
        if ('请选择日期' == pb1.innerText && '请选择日期' == pb2.innerText && pb3.options[4].selected) {  
            //首页显示本日的预警信息  
            sendStr = "IPAddress=" + IP + "&TradeCode=1607&PageCount=" + entry + "&PageIndex=1&Opt=S";  
            loadXMLDoc(sendStr, 3);  
            first = false;  
        } else {  
            sendStr = "IPAddress=" + IP + "&TradeCode=1607&PageCount=" + entry + "&PageIndex=1&Round=" + pb3.value + "&Start=" + clTime(pb1.innerText) + "&End=" + clTime(pb2.innerText) + "&Opt=ST";  
            loadXMLDoc(sendStr, 3);  
            first = false;  
        }  
    } else {  
        pageIndex1 = pageIndex1 + 1;  
        alert('第' + pageIndex1 + '次');  
        if ('请选择日期' == pb1.innerText && '请选择日期' == pb2.innerText && pb3.options[4].selected) {  
            sendStr = "IPAddress=" + IP + "&TradeCode=1607&PageCount=" + entry + "&PageIndex=" + pageIndex1 + "&Opt=S";  
            //alert("1" + sendStr);  
            loadXMLDoc(sendStr, 1);  
        } else {  
            sendStr = "IPAddress=" + IP + "&TradeCode=1607&PageCount=" + entry + "&PageIndex=1&Round=" + pb3.value + "&Start=" + clTime(pb1.innerText) + "&End=" + clTime(pb2.innerText) + "&Opt=ST";  
            //alert(2 + sendStr);  
            loadXMLDoc(sendStr, 1);  
        }  
    }  
}

    if ('请选择日期' == pb1.innerText && '请选择日期' == pb2.innerText && pb3.options[4].selected) {  
        //sendStr = "IPAddress=" + IP + "&TradeCode=1607&PageCount=" + entry + "&PageIndex=" + pageIndex1 + "&Opt=S";  
        //alert('默认' + sendStr);  
        mui('#topPopover').popover('toggle');  
        plus.nativeUI.showWaiting();  
        first = true;  
        setTimeout(function() {  
            mui('#pullrefresh').pullRefresh().pullupLoading();  
        }, 300);  
    }