html:
<input type="button"  class="form-control inpt4" id="fsyzm" value="发送验证码" onclick = "settime(this)">

js:
var countdown=60;
function settime(obj) {
     if (countdown == 0) {
         obj.removeAttribute("disabled");   
         obj.value="发送验证码";
         countdown = 60;
         return;
     } else {
         obj.setAttribute("disabled", true);
         obj.value="重新发送(" + countdown + ")";
         countdown--;
     }
setTimeout(function() {
     settime(obj) }
     ,1000)
}


jquery调用


settime('#fsyzm');


var countdown=60;
function settime(obj) {
  // var obj = $('#fsyzm');  
     if (countdown == 0) {
      $(obj).removeAttr("disabled");   
      $(obj).val("发送验证码");
         countdown = 60;
         return;
     } else {
      $(obj).attr("disabled", true);
      $(obj).val("重新发送(" + countdown + ")");
         countdown--;
     }
setTimeout(function() {
     settime(obj) }
     ,1000)
}