Problem With SQLBindParameter

I am developing an application, using ODBC, that needs to call a stored procedure in an SQL Server DBMS that has a mix of INPUT and INPUT_OUTPUT parameters. I have the code so that there aren't any errors returned from the function calls but I do not see the bound data change after the SQLExecute() function.

Code snippets follow.

CHAR szStatement[256];

CHAR szBuf[256];

SQLINTEGER irval = 0, filenum = 808042, DoNotCall = 0;
SQLVARCHAR vcPhoneNumber[PHONE_LEN];
SQLVARCHAR vcInstanceCode[INSTANCE_LEN] = {0x20};
SQLVARCHAR vcReason[REASON_LEN] = {0x20};
SQLINTEGER rvalLen = 0, fileLen = 0, noCallLen = 10, phoneLen = SQL_NTS, instanceLen = SQL_NTS, reasonLen = SQL_NTS;


lstrcpy( szStatement, "exec ?= some_proc ?, ?, ?, ?, ?" );

sqlr = SQLPrepare( hStmt, szStatement, lstrlen( szStatement ) );
sqlr = SQLBindParameter( hStmt, 1, SQL_PARAM_OUTPUT, SQL_C_LONG, SQL_INTEGER, 10, 0, &irval, 0, &rvalLen );
sqlr = SQLBindParameter( hStmt, 2, SQL_PARAM_INPUT, SQL_C_LONG, SQL_INTEGER, 10, 0, &filenum, 0, &fileLen );
sqlr = SQLBindParameter( hStmt, 3, SQL_PARAM_INPUT, SQL_C_CHAR, SQL_CHAR, 10, 0, vcPhoneNumber, 10, &phoneLen );
sqlr = SQLBindParameter( hStmt, 4, SQL_PARAM_INPUT, SQL_C_CHAR, SQL_VARCHAR, 50, 0, vcInstanceCode, 0, &instanceLen );
sqlr = SQLBindParameter( hStmt, 5, SQL_PARAM_INPUT_OUTPUT, SQL_C_LONG, SQL_INTEGER, 1, 0, &DoNotCall, 0, &noCallLen );
sqlr = SQLBindParameter( hStmt, 6, SQL_PARAM_INPUT_OUTPUT, SQL_C_CHAR, SQL_VARCHAR, 250, 0, vcReason, 0, &reasonLen );
sqlr = SQLExecute( hStmt );
if( sqlr == SQL_SUCCESS || sqlr == SQL_SUCCESS_WITH_INFO )

{
sprintf( szBuf, "The return value is %d", irval );
sprintf( szBuf, "The file number is %d", filenum );
sprintf( szBuf, "The phone number is %s", vcPhoneNumber );
sprintf( szBuf, "The instance code is %s", vcInstanceCode );
sprintf( szBuf, "The do not call value is %d", DoNotCall );
sprintf( szBuf, "The reason is %s", vcReason );
}

The problem is that in each of the function calls, the sqlr == SQL_SUCCESS but after the call to SQLExecute(), the data does not change for the output parameters. I can do something similar in other query tools that show the proper values but I am not getting the chanes in my bound variables. I tried adding a call to SQLParamData() but I was having a "Function sequence error" problem.



Any help would be very much appreciated. Thanks in advance.