function CheckEMail(Form) {
      var parsed = true;
      var validchars = "abcdefghijklmnopqrstuvwxyz0123456789@.-_";
      var email = Form.email.value;
  
      if (email.length == 0) {
        alert("请输入邮箱地址!");
        parsed = false;
      }
      else {
        if (email.indexOf("@") == -1) {
          alert("邮箱地址格式不正确!");
          parsed = false;
        }
        else {
          for (var i=0; i < email.length; i++) {
            var letter = email.charAt(i).toLowerCase();
            if (validchars.indexOf(letter) != -1)
              continue;
            alert("无效字符: '" + letter + "'.");
            parsed = false;
            break;
          }
        }
      }
      return (parsed);
		}