Charleston’s odds continue to improve in an online contest to determine what city will win $1 million from Wal-Mart for local food banks.

Charleston’s rank in the promotion rose today from 36 to 20.

Wal-Mart Stores Inc. has agreed to give $1 million to the community that gets the most votes in a contest running on its Facebook page. The food giant will provide $100,000 each to the next five communities. The money would go to local food banks.

The contest runs until Dec. 31, and each visitor may vote only once, which is in line with standard Facebook rules.

Mickey Bakst, general manager of Charleston Grill, is trying to rally the community to get online and start clicking. Hundreds of people have done just that.

“Charleston has the reputation of being polite and gracious ,” posted city resident Fletcher Derrick. “This includes being helpful to those in need.”

“Let’s help our neighbors,” added Emilie Costikyan. “It’s shocking that 20% of families in our community cannot afford regular meals. That’s 1 in 5 families!”

Leading the way in the contest are Fresno, Cal.; Grand Rapids, Mich., and Salt Lake City. South Carolina’s capital city, Columbia, is in the No. 6 slot, with 5,659 supporters.

Charleston is on the list because it was identified as having one of the highest hunger rates in the country. But it is also competing with 99 other communities.

Wal-Mart relied on the Food Research and Action Center to come up with the list of 100 communities.

Bakst said the effort is too simple to not get widespread participation. He spent part of the day Thursday blasting out e-mails and trying to get local media, hospitals, tourism and public relations sources involved in getting the word out — a message he said needs to be repeated, stressed and advertised daily.

If it comes true? “What a great thing,” he said.