setting proxy for apt-get

[Asep Andria I.W.]

Hello All,

I've just install Ubuntu 5.04 on my PC. I have a problem with apt-get.
How do I set the authentication for apt-get for proxy user and proxy 
password?

I try this way :
export http_proxy=http://172.16.1.71:8080/

where to input the user and password for my proxy ?

Thanks for your help.