Jquery ajax的进来帮忙看下。一个登陆验证的问题

    <li>
                                <input type="text" name="username" id="username" placeholder="个人标识" value="" required="required"  data-clear-btn="true" data-msg-required="个人标识不能为空。">
                                <label for="username" class="error"></label>
                            </li>
                            <li>
                                <input type="password" name="userpassword" id="userpassword" placeholder="个人密码" value="" required="required" data-clear-btn="true" data-msg-required="个人密码不能为空。" />
                                <label for="userpassword" class="error"></label>
                            </li>
                            <li>
                                <input id="txtVildateCaptcha" type="text" name="txtVildateCaptcha" style="width:200px" /><mobile:CaptchaImg runat="server"></mobile:CaptchaImg>
                              
                            </li>
                            <li>
                                <input type="button" id="loginbutton" name="loginbutton" value="登  陆" data-role="button" data-theme="b" onclick="login();" />
                                <label id="errortxt" for="loginbutton" class="error"></label>
                            </li>   if (($(document.forms[0]).validate().form())) {
                        $("#loginbutton").prop("disabled", true);
 
                        $.eias.mobile.get({
                            url: 'System/UserService.svc/logon/?pid=' + $('#username').val() + '&pwd=' + $('#userpassword').val(),
                            success: function (result) {
                                if (result == true) {
                                    $("#errortxt").hide();
                                    var str = $.eias.mobile.getQueryValue("ReturnUrl");
                                    if (!str) {
                                        str = mobilePath + "default.aspx";
                                    }
                                    window.location.href = str;
                                } else {
                                    $("#loginbutton").prop("disabled", false);
                                    $("#errortxt").show().html("登陆失败！用户名或密码错误。");
                                }
                            },
                            complete: function () {
                                $("#loginbutton").prop("disabled", false);
                            }
                        });
接口
登陆验证jQuery Ajax