function check() {
    var formcheck = document.getElementById("search");
    if (formcheck.contentxx.value == "" || formcheck.contentxx.value.length == 0) {
        event.returnValue = false;
        alert("请填写问题内容");
        return false;
    }
    
    if (formcheck.name.value == "" || formcheck.name.value.length == 0) {
        event.returnValue = false;
        alert("请填写联系人");
        return false;
    }
    
    if (formcheck.tel.value == "" || formcheck.tel.value.length == 0) {
        event.returnValue = false;
        alert("请填写联系电话");
        return false;
    }
    alert("咨询成功，谢谢您对我们网站的支持！");
}