I'm a Newbie and need help

[Snickers]

I have a 4 month old female maltese that I'm trying to litter train. She will use the litterbox while I am at work, but when I'm home she pees on the floor right in front of the litterbox. When she needs to poop she always uses the litterbox. I give her lots of attention, but right now I'm at my wits end with her. A couple of times I rubbed her nose in it, then tried timeouts where she's confined to a doorknob for a few minutes, and for the last week I've just wiped it up without saying anything and ignoring her for a little while. Nothing I'm doing is helping. Please if anyone has any ideas they would be most welcome. Thanks