FileUploader, how to add Parameters?

Hi experts,

I'm trying to import an excel file into a table using the FileUploader control.

For that i need to send the table content to the backend together with the file.

I saw there is a property parameters[] in this control, but i don't really get it how to use it.

In the "change" event from the control, I'm trying to add some parameters, but it doesn't accept them with fileUploader.addParameter("someContent")

What kind of values does this method accept?

and what is the best way to send some data to the backend through the fileUploader control?

Regards,

Georgi