在AJAX成功后清除文本框

Question

我对为什么这不起作用感到困惑。我只想在请求成功后清除文本框。成功设置的功能是否错误？我刚开始使用AJAX和JavaScript，因此任何建议都很棒！ 这是完整的功能，可让您更全面地了解整体功能。

function txtChk() {
    var controls = 0;
    /* ----------------------------------------------- 
     DECLARING OBJECTS TO HOLD ALL CONTROLS
    ----------------------------------------------- */
    const labels = document.getElementsByClassName('inputLabel');
    const texts = document.getElementsByClassName('gezza-field');
    var rdbYes = document.getElementById("<%=rdbYes.ClientID%>");
    var rdbNo = document.getElementById("<%=rdbNo.ClientID%>");
    var rdbYesLead = document.getElementById("<%=rdbYesLead.ClientID%>");
    var rdbNoLead = document.getElementById("<%=rdbNoLead.ClientID%>");
    var first = document.getElementById("<%=txtFirst.ClientID%>");
    var last = document.getElementById("<%=txtLast.ClientID%>");
    var phone = document.getElementById("<%=txtPhone.ClientID%>");
    var email = document.getElementById("<%=txtEmail.ClientID%>");
    const radiosRef = document.getElementsByClassName('referral');
    const radiosLead = document.getElementsByClassName('lead');

    /*--------------------------------------------------------
       RUNNING FOR LOOPS THROUGH DECLARED OBJECTS TO 
       HANDLE ANY ERRORS (TERNARY OPERATORS INSIDE FORS)
       (SECOND EDIT)
     ------------------------------------------------------- */
     for (var i = 0; i < 4; i++) {
         labels[i].style.color = (texts[i].value == "" ? "FireBrick" : "Black");
         labels[i].innerHTML = (texts[i].value == "" && 
         labels[i].innerHTML.charAt(0) != "*" ? "*" + labels[i].innerHTML : labels[i].innerHTML);
        }
    labels[4].innerHTML = (rdbYesLead.checked == false && rdbNoLead.checked == false ? "*Please select one" : "");
    controls = (rdbYesLead.checked == false && rdbNoLead.checked == false ? controls : controls + 1);

    labels[5].innerHTML = (rdbYes.checked == false && rdbNo.checked == false ? "*Please select one" : "");
    controls = (rdbYes.checked == false && rdbNo.checked == false ? controls : controls + 1);

    for (var l = 0; l < 4; l++) {
        if (texts[l].value != "") {
            controls += 1;
        }
    }
    if (controls < 6) {
        alert("Fix all errors before submitting");
        return false;
    }
    else {
        var referral = rdbYes.checked == true ? 1 : 0;
        var lead = rdbYesLead.checked == true ? 1 : 0;
            $.ajax({
                type: "POST",
                contentType: "application/json; charset=utf-8",
                url: "Default.aspx/updateDB",
                data: "{'first':'" + first.value + "','last':'" + last.value + "','phone':'" + phone.value + "','email':'" + email.value + "','referral':'" + referral + "','lead':'" + lead + "'}",
                dataType: "json",
                success: function (response) {
                    alert("Thank you, " + first.value + "!");
                    first.value = "";
                    last.value = "";
                    phone.value = "";
                    email.value = "";
                    },
                    error: function () {
                        alert("Error! Connection was lost, please try again");
                    }
                });


            //first.value = "";
            //last.value = "";
            //phone.value = "";
            //email.value = "";
            //rdbNo.checked = false;
            //rdbYes.checked = false;
            //rdbNoLead.checked = false;
            //rdbYesLead.checked = false;
        }
    }