How do I make a thin line with the Pen Tool? [PS & +REP]

[Meti]

Hi guys,

I'm using Photoshop CS3 Extended, and know how to use the Pen Tool.
But I want to know how to make the line like 1 px thin. Does anyone know how to do this?
I'd be happy to give +REP to the person who helps me.

Do you understand what I mean?

Thanks,
Meti

[Excellent2]

Just click along that line

[Meti]

Err. I'll try it.
Thanks, +rep in advance