Thanks for your help.

Suppose Al, Jack, and Ted helped me with my corn cultivation by teaching me how to plow, sow seeds, water, reap for a couple of years. They are in front of me now. I'd like to tell them my thanks. In this situation, which is better to say, #1 or #2?

#1: Thanks for your help.
#2: Thanks for your helps.

Suppose Al, Jack, and Ted helped me with my corn cultivation by teaching me how to plow, sow seeds, water, reap for a couple of years. Al is in front of me now and Jack and Ted aren't. I'd like to tell Al my thanks. In this situation, which is better to say, #3 or #4?

#3: Thanks for your help.
#4: Thanks for your helps.