极品菜鸟裸体跪求急待解决！！！！
Personal personal = new Personal() ;

if(usn.Text == " ") Response.Write ( " <script language=javascript> alert( '用户名不能为空 '); </script> ");
else if (pwd.Text == " ") Response.Write( " <script language=javascript> alert( '密码不能为空 '); </script> ");
else
{
personal.Code = usn.Text;
int i = personal.GetPersonalInfo();
if (i!=0)
{ Response.Write( " <script language=javascript> alert( '登陆失败 '); </script> "); return; }
if (personal.CheckPWD(pwd.Text))
{
Session.Add( "Authors ", personal);
}


}
if (personal.ChangePWD(opwd.Text))
{
Session.Add( "Authors ", personal);

Response.Write( " <script language=javascript> alert( '恭喜您密码修改成功 '); </script> ");

}
else
{ Response.Write( " <script language=javascript> alert( '登陆失败 '); </script> "); return; }

}

２个对象分别是这样的｀｀
/// 核对密码
/// </summary>
/// <param name= "PWD "> 要核对的密码串 </param>
/// <returns> true正确，false错误 </returns>
public bool CheckPWD(string PWD)

{
if (this._flag)
{
return this._pwd == PWD;
}
else
{
return false;
}
}

/// <summary>
/// 修改密码
/// </summary>
/// <param name= "OldPWD "> 旧密码 </param>
/// <param name= "NewPWD "> 新密码 </param>
/// <returns> 1 成功，其他错误 </returns>
public int ChangePWD(string OldPWD, string NewPWD)
{
if (CheckPWD(OldPWD) && NewPWD.Trim() != " ")
{
string strSql = "update tab_operator set ppass = ' " + NewPWD + " ' where ccode = ' " + this._code + " ' ";
DataHelper.SqlHelper.ExecuteNonQuery(GasWebDll.strMainConn, CommandType.Text, strSql);
this._pwd = NewPWD;
return 0;
}
else
{
return -1;
}
}
麻烦谁给讲解一下｀｀｀

------解决方案--------------------

２个对象分别是这样的｀｀
/// 核对密码
/// </summary>
/// <param name= "PWD "> 要核对的密码串 </param>
/// <returns> true正确，false错误 </returns>
public bool CheckPWD(string PWD)
{
if (this._flag)
{
return this._pwd == PWD;
}
else
{
return false;
}
}


返回值错误吧...pwd不是string型吗？