将excel导入到sql中报错：找不到可安装的 ISAM。 ！！！谁帮帮我啊》？
代码如下：
string fullfilename = this.FileUpload1.PostedFile.FileName;
  string filename = fullfilename.Substring(fullfilename.LastIndexOf("\\") + 1);
  string type=fullfilename.Substring(fullfilename.LastIndexOf(".")+1);
  if(type!="xls" || filename!="数据库文件.xls")
  {
  Jscript.Alert("您选择的文件不正确！");
  }
  else
  {
   
  string mystring = "Provider=Microsoft.Jet.OLEDB.4.0;Data Source= '" + fullfilename + "';Extended Properties=Excel 8.0";
  OleDbConnection cnnxls = new OleDbConnection(mystring);
  OleDbDataAdapter myDa = new OleDbDataAdapter("select * from [Sheet1$]", cnnxls);
  DataSet myDs = new DataSet();
  myDa.Fill(myDs);/////////////////////////////////在这里报错！！！！！ 报错：找不到可安装的 ISAM！！

  if (myDs.Tables[0].Rows.Count > 0)
  {
  string strSql = "";
  string CnnString = "Provider=SQLOLEDB;database=HSSTORE;server=(local);uid=sa;pwd=wwwwww";
  OleDbConnection conn = new OleDbConnection(CnnString);
  conn.Open();
  OleDbCommand myCmd = null;

  for (int i = 0; i < myDs.Tables[0].Rows.Count; i++)
  {
  strSql = "insert into A(A,B) values ('";
  strSql += myDs.Tables[0].Rows[i].ItemArray[1].ToString() + "', '";
  strSql += myDs.Tables[0].Rows[i].ItemArray[2].ToString() + "')";

  try
  {
  myCmd = new OleDbCommand(strSql, conn);
  myCmd.ExecuteNonQuery();
  Jscript.Alert("数据导入成功！");
  }
  catch
  {
  Jscript.Alert("数据导入失败！");
  }
  }
  conn.Close();
  }  

  }

------解决方案--------------------
连接字符串错误 ，把mystring 打印出来看一下
------解决方案--------------------
up