Is there a way to to a fill with diagonal lines in PS CS3?

I have a document that has outlines of the counties in our state on a layer. I'd like to fill some with a series of diagonal lines with alternating foreground/background color. Is there an easy way to do this?

If I use the gradient tool, I have to make a selection on a specific county I want to set and apply the gradient that way. From my testing tonight, it's not simple or easily repeatable. If there's a way to do a simple diagonal line type fill or some other combination of foreground/background colors that are easily repeatable and consistent, I haven't figured out how to do it. I'm appealing to the CS3 gurus out there for help.

Difference clouds are a possibility, but they're not really consistent and not the look I'm going for. Plus, I'd still have to make a selection on each county where I'd need to apply it.

Any other thoughts or ideas out there?

Take a look at the Custom Shape Tool for a series of 1-color diagonal lines.

'Define pattern' is the thing you want I think.

Linky

I tried to answer this yesterday, but my computer at work was being obnoxious.

PhotosGuy wrote in post #7159893
Take a look at the Custom Shape Tool for a series of 1-color diagonal lines.

I actually found and tried that not long after I posted, but I discovered it was a little problematic as well. The diagonal shape wanted to draw in rectangular format, which I then ended up having to go back and mask/erase the parts I didn't want. Plus, the lines varied in size with the size of the box I was trying to fill. If I'd only had one or two to do, it would have been my first choice, but I had 21 to do.

smdevo wrote in post #7160379
'Define pattern' is the thing you want I think.
Linky

This was what I ended up doing. Thanks for the idea!
I'd never done a custom pattern before, and though it took some time to get the pattern setup like I wanted, I think the end result came out pretty decent. The color combination was not ideal (red/green), but I was limited to those based on what I wanted to do.

If anyone wants to see the final product, I'll post it as soon as it's online. Thanks for the help!