data inserting problem

Dear Sirs, I am using following script to insert data into ms access data with php script $UserName = "ara"; $Password = "123456"; $conn = new COM("ADODB.Connection") or die("Cannot start ADO"); // Microsoft Access connection string. $conn->Open("DRIVER={Microsoft Access Driver (*.mdb)}; DBQ=C:\\Xitami\\webpages\\sig.mdb"); $sql = "INSERT INTO Users (UserName,Password) values (" .$conn->qstr($UserName).',' //line 20 .$conn->qstr($Password).")"; //line 21 $conn->Execute($sql); But I am getting following error; ------- Warning: (null)(): Invoke() failed: Exception occurred. Source: ADODB.Connection Description: Arguments are of the wrong type, are out of acceptable range, or are in conflict with one another. in C:\XITAMI\webpages\php\temp\AddData.php on line 20 Warning: (null)(): Invoke() failed: Exception occurred. Source: ADODB.Connection Description: Arguments are of the wrong type, are out of acceptable range, or are in conflict with one another. in C:\XITAMI\webpages\php\temp\AddData.php on line 21 Warning: (null)(): Invoke() failed: Exception occurred. Source: Microsoft OLE DB Provider for ODBC Drivers Description: [Microsoft][ODBC Microsoft Access Driver] Syntax error in INSERT INTO statement. in C:\XITAMI\webpages\php\temp\AddData.php on line 22 ------- What do I need to do? I presuate any web source which is explaining ms access data handling Best Regards