Is Benching Legal

Is the Benching legal ?.
I came to US with H1B visa in October 11 2009. I start in a project for 3 months. Now I have one month without project and without salary.
My employer request to me write a letter where I'm requesting a "leave of absence". It is legal?. What if I write that letter, what if not.

I want return to my country for few months because I have business there.
I'm here losing money.

Another question. When the consulate stamp my h1b visa, canceled my B1/B2 visa. If I decide to return to my country, is there a procedure to revert my h1b to b1/b2 visa?.. or do I had to re-apply for a B1/B2 visa.

Thanks.

If you're "benched", that means they don't have work for you but continue to pay you. You remain in status.

If you're "laid off", that means they don't have work for you, stop paying you, and suspend your employment relationship. You go out of status.

You are in H1B status, not B1/B2 status. If you want a B1/B2 visa, you need to apply for one.