Continue to work across the row, knitting a stitch in one color and purling a stitch in the other color, across the row. If you used the two-color cast on, you can drop the slip knot when you get to the end of the row.
By Sarah E. White, About.com Guide
Continue to work across the row, knitting a stitch in one color and purling a stitch in the other color, across the row. If you used the two-color cast on, you can drop the slip knot when you get to the end of the row.