FROM 子句语法错误。
using System;
using System.Data;
using System.Configuration;
using System.Web;
using System.Web.Security;
using System.Web.UI;
using System.Web.UI.WebControls;
using System.Web.UI.WebControls.WebParts;
using System.Web.UI.HtmlControls;
using System.Data.OleDb;
using System.IO.Compression;
using System.IO;
using System.Text;
using System.Collections.Generic;



public partial class _Default : System.Web.UI.Page 
{
  protected void Page_Load(object sender, EventArgs e)
  {

  }
 protected void LoginButton_Click1(object sender, EventArgs e)
  {

  OleDbConnection con = new OleDbConnection("Provider=Microsoft.Jet.OLEDB.4.0; Data Source=" + Server.MapPath(".") + "..\\data\\name.mdb;");
  con.Open();
  string u = UserName.Text;
  string p = Password.Text;
  OleDbCommand d = new OleDbCommand("SELECT * FROM in where id='"+u+"' and pw='"+p+"'", con);
   

  int i = Convert.ToInt32(d.ExecuteNonQuery());
  if (i > 0)
  {
  Response.Redirect("index.aspx");
  }
  else
  {
  Response.Redirect("error.aspx");
  }

  }
}


错误：： 

FROM 子句语法错误。 
说明: 执行当前 Web 请求期间，出现未处理的异常。请检查堆栈跟踪信息，以了解有关该错误以及代码中导致错误的出处的详细信息。 

异常详细信息: System.Data.OleDb.OleDbException: FROM 子句语法错误。

源错误: 


行 32:  
行 33: 
行 34: int i = Convert.ToInt32(d.ExecuteNonQuery());
行 35: if (i > 0)
行 36: {
 

源文件: c:\Documents and Settings\Administrator\桌面\sine\landing.aspx.cs 行: 34 

堆栈跟踪: 


[OleDbException (0x80040e14): FROM 子句语法错误。]
  System.Data.OleDb.OleDbCommand.ExecuteCommandTextForSingleResult(tagDBPARAMS dbParams, Object& executeResult) +177
  System.Data.OleDb.OleDbCommand.ExecuteCommandText(Object& executeResult) +194
  System.Data.OleDb.OleDbCommand.ExecuteCommand(CommandBehavior behavior, Object& executeResult) +56
  System.Data.OleDb.OleDbCommand.ExecuteReaderInternal(CommandBehavior behavior, String method) +105
  System.Data.OleDb.OleDbCommand.ExecuteNonQuery() +88
  _Default.LoginButton_Click1(Object sender, EventArgs e) in c:\Documents and Settings\Administrator\桌面\sine\landing.aspx.cs:34
  System.Web.UI.WebControls.Button.OnClick(EventArgs e) +75
  System.Web.UI.WebControls.Button.RaisePostBackEvent(String eventArgument) +97
  System.Web.UI.WebControls.Button.System.Web.UI.IPostBackEventHandler.RaisePostBackEvent(String eventArgument) +7
  System.Web.UI.Page.RaisePostBackEvent(IPostBackEventHandler sourceControl, String eventArgument) +11
  System.Web.UI.Page.RaisePostBackEvent(NameValueCollection postData) +33
  System.Web.UI.Page.ProcessRequestMain(Boolean includeStagesBeforeAsyncPoint, Boolean includeStagesAfterAsyncPoint) +4921




------解决方案--------------------
你的表名是叫in吗？
如果是的话，加个中括号试试
OleDbCommand d = new OleDbCommand("SELECT * FROM [in] where id='"+u+"' and pw='"+p+"'", con);
------解决方案--------------------
SELECT * FROM in where id='"+u.Replace("'","")+"' and pw='"+p.Rep