图片验证码

html:

<div id="code1">
    <input class="text-input" type="text" name="code1" placeholder="验证码"/>
    <img src="" alt="" class="captcha" onclick="get_captcha();" align="验证码" title="看不清？换一张" style="cursor:pointer;position: absolute;right:0; 85px;height:40px;top:5px;"/>
</div>

<div id="next">登录</div>
JQ:

//点击登录
$('#next').click(function(){

  var captcha_code = $('[name = "code1"]').val();
  var captcha_id = $('.captcha').attr('data-id');
  var telphone = $('[name = "telphone"]').val();
  var pwd = $('[name = "pwd"]').val();
//登录接口

$.post("/sign",{
    captcha_id:captcha_id,
    captcha_code:captcha_code,
    login: telphone,
    password: pwd,
    web:true  //网页登录
},function(data){
    if(data.status == 200){
        $("#next").css({'background-color':'#3B5999','opacity':'0.5'});
        $("#next").text('载入中...');
            if(parame == 'index'){ //索引
                window.location.href = '/index.html?login='+telphone+'&access_token='+data.data.access_token;
            }    
      }
    else{
        alert(data.error);
    }
})

//获取验证码图片
function get_captcha(){
    $.get(
         '/captcha/captchaid',function(data){
            $('.captcha').attr('src','/captcha/captcha?id=' + data.data);
            $('.captcha').attr('data-id',data.data);
         }
     );
}