DataSource Controls :: Sqldatasoure, Mysqldatareader And Stored Procedures?

I am having a problem returning a value from a stored procedure when using SqlDataSource. The stored procedure is executing because 'invoice_no is incrementing but Myreader.HasRows is always false.

Here is the table definition

`invoice_no` int(10) NOT NULL AUTO_INCREMENT,
`employee` varchar(50) DEFAULT NULL,
`create_date` timestamp NULL DEFAULT CURRENT_TIMESTAMP,
PRIMARY KEY (`invoice_no`)

Here is the stored procedure:

CREATE PROCEDURE `GetInvoiceNumber`(IN username VARCHAR(50), OUT InvoiceNum INT)
BEGIN
INSERT INTO invoice (employee)
VALUES (username);
SELECT MAX(invoice_no) INTO InvoiceNum FROM invoice;
END

And here is my code.

[Code]....