The Rules

ok, I don't know .. so please don't shoot me for asking.
I found a pattern, I would like to make this pattern w/ a few changes (not
just color, but design as well)
I would like to sell the finished product.
Can I with out violating any copy right laws?
I won't be giving the pattern out ... just selling a couple at a local art
show and I will be making changes, adding beads, using another type of yarn,
adding a border so that the edge isn't the same.