function yz()
  {
    if(empty($_POST))
    {
      $this->display();
    }
    else
    {
      $db=D("Info");
       
      $shu=array(
        array("Code","require","代号不能为空",0,"regex",3),
      );
       
      if(!$db->validate($shu)->create())
      {
        echo $db->getError();
      }
      else
      {
        echo"验证通过";
      }
    }
  }

function ming()
  {
    $code=$_POST["code"];
    $db=D("Info");
    $data=$db->find($code);
    $name=$data["name"];
    $this->ajaxReturn($name,"eval");
  }

<input id="zhi" type="text" name="Code" />
<input type="submit" value="验证" id="en" />

<script type="text/javascript">
$(document).ready(function(e){
  $("#en").click(function(){
    var code=$("#zhi").val();
    $.ajax({
       url:"__CONTROLLER__/ming",
       data:{code:code},
       type:"POST",
       dataType:"TEXT",
       success: function(data){
           alert(data);
         }
      });
    })
    $("#yz").blur(function(){
      var code=$(this).val();
      $.ajax({
       url:"__CONTROLLER__/yan",
       data:{Code:code},
       type:"POST",
       dataType:"TEXT",
       success: function(data){
           if(data.trim() == "ok")
           {
             $("#xs").html("验证通过！");
             $("#xs").css("color","green");
           }
           else
           {
             $("#xs").html(data);
             $("#xs").css("color","red");
           }
         }
      });
    })
  });

function yan()
  {
      $db=D("Info");
      $jieguo="";
      $shu=array(
        array("Code","require","代号不能为空",0,"regex",3),
      );
       
      if(!$db->validate($shu)->create())
      {
        $jieguo= $db->getError();
      }
      else
      {
        $jieguo="ok";
      }
      $this->ajaxReturn($jieguo,"eval");
  }