A Madison man selling an ounce of marijuana to two would-be buyers ended up getting beaten and robbed instead, with the seller calling police and the attackers getting arrested a short time later, according to police.

Kenneth Johnson, 18, Madison, was tentatively charged with strong-arm robbery and Clarence Smith, 20, Madison, was tentatively charged with battery, according to a Madison police news release.

Police said the seller got into the buyers' van on the 1900 block of Elka Lane on the city's north side and produced the pot which he was going to sell for $300.

"Instead of producing cash, the suspects pulled him out of the van and allegedly punched him, saying they were not going to pay," said police spokesman Joel DeSpain.

The seller notified police who pulled the van over a short time later and made the arrest.

The pot seller was not charged.