I upload Excel File , but get other format file, Why?

Hello,

I upload files whose format is Excel in BSP. But sometimes I get those files whose format is WAR . The following is that I gain the files type Code:

DATA: data TYPE REF TO cl_htmlb_fileupload,

type1 type string .

CLEAR data.

data ?= cl_htmlb_manager=>get_data(

request = runtime->server->request

name = 'fileUpload'

id = fieldname

).

type1 = data->file_content_type .

Who had solved this problem , give a hand please .