如何在window.location重定向后向HTML元素添加文本

Question

使用jQuery我试图在id函数重定向后通过window.location向HTML元素添加文本。基本上是为了显示错误信息。

HTML.ERB

         <p><%= text_field_tag 'birthday', nil, placeholder: 'mm/dd/yyyy'  %></p>
         <p id="birthday"></p>

的jQuery / JS

<% content_for :tail do %>
  <script type="text/javascript">
    $("#leading_health_yes_btn").on('click', function(){
      var x = $("#gender").val();
      var y = $("#hh_size").val();
      var z = $("#birthday").val();
      if ( validateBirthday(z) ){
        $.ajax({ url: "/host_and_post/select?partner=LeadingHealthQuotes&gender="+x+"&hh_size="+y+"&birthday="+z });
      } else {
        window.location = "/sponsors";
        $("#birthday").text("MUST BE mm/dd/yyyy FORMAT");
      }
    });
    function validateBirthday(birthday){
      var regexDate = /^((0?[1-9]|1[012])[- /.](0?[1-9]|[12][0-9]|3[01])[- /.](19|20)?[0-9]{2})*$/
      return regexDate.test(birthday);
    };
  </script>
<% end %>