JSP结合js实现img中src更新请求的方法

<script type="text/javascript"> function changeImage(){   var img = document.getElementById("imgVcode");  if(img.name == 1){     img.name = 2;     img.src = "shop.do?method=registerImage2";  }else if(img.name == 2){     img.name = 1;     img.src = "shop.do?method=registerImage";  } } </script>

<td>   <img class="yzm_img" id='imgVcode' name="1" src="shop.do?method=registerImage" />  <input name="code" type="text" id="txtVerifyCode"     class="yzm_input" onblur="testCode(this)"/>  <div class="text_left t1">    <p class="t1">      <span id="vcodeValidMsg">请输入图片中的四个字母。</span>       <span id="codeInfo" style="color:red"></span>       <a href="#" id="imgchange" onclick="changeImage()">看不清楚？换个图片</a>    </p>   </div> </td>

public ActionForward registerImage(ActionMapping mapping, ActionForm form,    HttpServletRequest request, HttpServletResponse response)    throws Exception {     //将image创建,返回认证码     response.setContentType("image/jpeg");     OutputStream out = response.getOutputStream();     String strEnsure = shopManager.createImageInfo(50,20,out);    //设置到session中     request.getSession().setAttribute("strEnsure", strEnsure);    return null;   }   public ActionForward registerImage2(ActionMapping mapping, ActionForm form,       HttpServletRequest request, HttpServletResponse response)      throws Exception {     //将image创建,返回认证码     response.setContentType("image/jpeg");     OutputStream out = response.getOutputStream();     String strEnsure = shopManager.createImageInfo(50,20,out);    //设置到session中     request.getSession().setAttribute("strEnsure", strEnsure);    return null; }