text: window.onload=function(){
  
      document.onkeydown = function(event) {
          var target, code, tag;
          if (!event) {
              event = window.event; //针对ie浏览器
              target = event.srcElement;
              code = event.keyCode;
              if (code == 13) {
                  tag = target.tagName;
                  if (tag == "TEXTAREA") { return true; }
                  else { return false; }
              }
          }
          else {
              target = event.target; //针对遵循w3c标准的浏览器，如Firefox
              code = event.keyCode;
              if (code == 13) {
                  tag = target.tagName;
                  if (tag == "INPUT") { return false; }
                  else { return true; }
              }
          }
      }
  
      var password=document.getElementById('password');
      var pwdcheck=document.getElementById('pwdcheck');
      password.onfocus=function(){
          pwdcheck.style.display='block';
      }
  }