layui 驗證 判斷值只能中文(姓名、用戶名)

 <input type="text" name="username" id="username" required  lay-verify="required|username" value="{$rsu['real_name']}" placeholder="真實姓名" autocomplete="off" class="layui-input">

<script>
layui.use(['form','jquery','layer'], function(){
      var layer = layui.layer
      ,form = layui.form
      ,$= layui.$;
      
      
		form.verify({
		  username: function(value, item){ //value：表單的值、item：表單的DOM對象
		    if(!new RegExp("^[\u4e00-\u9fa5\]+$").test(value)){
		      return '姓名只能是中文';
		    }

		  }
		});

      
      
});
</script>