Error Unable to open file in an excel agent

Hello all:I have an excel agent that runs this code on a web browser

Print “Content-Type:application/vnd.ms-excel”

filenum = Freefile()

filename = "c:" & viewname & “.csv”

Open filename For Output As filenum

but I get an error in the open statement

08/31/2003 15:14:28 Agent ‘my excel agent’ error: Unable to open file

I think I cannot get the browser to open the excel file ,did any one do this before

thanks

Dalia