连接ACCESS数据库的怪问题?

[mqcj]

大家帮我看看下面的程序,哪里有问题啊,连接是打开了,但是当执行到OleDbDataReader ar=myCmd.ExecuteReader();的时候,为什么老是要报错啊,说From子句有错啊,错误信息我已经贴在下面了,快帮帮我吧.谢了
string strDSN = "Provider=Microsoft.Jet.OLEDB.4.0;Data
Source=c:\\Cash.mdb";
string strSQL="SELECT UserName FROM User";
OleDbConnection myConn = new OleDbConnection(strDSN);
OleDbCommand myCmd = new OleDbCommand( strSQL, myConn );
myConn.Open();
OleDbDataReader ar=myCmd.ExecuteReader();
if (ar.Read())
{
return true;
}
else
{
return false;
}





See the end of this message for details on invoking
just-in-time (JIT) debugging instead of this dialog box.

************** Exception Text **************
System.Data.OleDb.OleDbException: FROM 子句语法错误。
at System.Data.OleDb.OleDbCommand.ExecuteCommandTextErrorHandling(Int32 hr)
at System.Data.OleDb.OleDbCommand.ExecuteCommandTextForSingleResult(tagDBPARAMS dbParams, Object& executeResult)
at System.Data.OleDb.OleDbCommand.ExecuteCommandText(Object& executeResult)
at System.Data.OleDb.OleDbCommand.ExecuteCommand(CommandBehavior behavior, Object& executeResult)
at System.Data.OleDb.OleDbCommand.ExecuteReaderInternal(CommandBehavior behavior, String method)
at System.Data.OleDb.OleDbCommand.ExecuteReader(CommandBehavior behavior)
at System.Data.OleDb.OleDbCommand.ExecuteReader()
at CashManager.DBOpt.CheckUser(String UserName, String Password) in c:\cashmanager\cashmanager\dbopt.cs:line 30
at CashManager.Form1.bntOK_Click(Object sender, EventArgs e) in c:\cashmanager\cashmanager\frmlogin.cs:line 209
at System.Windows.Forms.Control.OnClick(EventArgs e)
at System.Windows.Forms.Button.OnClick(EventArgs e)
at System.Windows.Forms.Button.PerformClick()
at System.Windows.Forms.Form.ProcessDialogKey(Keys keyData)
at System.Windows.Forms.Control.ProcessDialogKey(Keys keyData)
at System.Windows.Forms.Control.PreProcessMessage(Message& msg)
at System.Windows.Forms.ThreadContext.System.Windows.Forms.UnsafeNativeMethods+IMsoComponent.FPreTranslateMessage(MSG& msg)