upload files

Hi,Dear All:

I am asking for help here.

a local txt file,contain data which are refer to the data of table SPFLI.I want to call FM GUI_LOAD,So,first I must to build a internal table,and then transfer the data to it.but I am not clear with the structrue of this internal table.and after upload the file,i want to process each fields of the internal table separately(eg.to get each fields's value and then assign to a variant)

Pls give me a demo of upload files.