Authorities say an armed robber was foiled at a Madison, Wisconsin, convenience store when he cut the clerk's finger and her blood made it impossible to open the cash drawer with the register's computer screen.

The State Journal reports the robbery occurred around 9:25 p.m. Monday at a 7-Eleven. Police say a masked suspect was armed with a box cutter and sliced the woman's finger when he charged at her.

Police say the cash drawer is controlled by a computer touch screen that does not function when wet.

The robber instead grabbed some cigarettes and fled to a getaway car. The suspect remains on the loose.