设置5秒后按钮可以再次使用

function btn_refresh(btnName,btnValue)
 {
  var btn = document.getElementsByName(btnName);
  btn[0].disabled = true;
  btnIntervalId = window.setInterval("set_refresh_btn('"+btnName+"','"+btnValue+"')", 1000);
 }
 function set_refresh_btn(btnName,btnValue)
 {
  var btn = document.getElementsByName(btnName);
  btnSecond = btnSecond -1;
  if(btnSecond < 0){
   btn[0].value = btnValue;
   window.clearInterval(btnIntervalId);
   btnSecond = refreshInterval;
   btn[0].disabled = false;
  }
  else{
   btn[0].value = btnValue + '(' + btnSecond + ')';
  }
 }