javascript点击才出现验证码_javascript技巧

alert('请输入验证码！');history.go(-1);" Session("GetCode")=empty response.End() elseif lcase(code)lcase(Session("GetCode")) then response.write "" Session("GetCode")=empty response.End() Else Response.Write "" response.End() end if end if %> <form name="form" method="post" action="index.asp"> <tr> <td style="width:100px; text-align:right">验证码：</td> <td style="width:150px; text-align:left"> <p> <input type="text" name="code" id="code" size="4" maxlength="4" tabindex="6" onfocus="get_Code();this.onfocus=null;" onkeyup="dv_ajaxcheck('checke_dvcode','code');"><span id="imgid" style="color:red">点击获取验证码</span><span id="isok_code"></span></p> <input name="cur_action" type="hidden" value="add"><input name="提交" type="submit" id="提交"> </td> </tr> </form>
[Ctrl+A 全选 注:如需引入外部Js需刷新才能执行]