The day after 13 people were gunned down at a Colorado school, junior Rebecca Hunter of Hillsboro High School in Nashville, Tenn., had an idea.

It didn’t have anything to do with dress codes or police in the hallways or metal detectors at the doors. She and her class-mates in an American Studies course instead came up with a pledge to no longer taunt those who dress, talk or act differently.

Students and teachers are spreading copies of the pledge throughout the country via computer. The idea has intrigued teachers as far away as California.

The pledge was signed by 850 students in one day at Green Mountain High School in Jefferson County, Colorado., the same county where Eric Harris, 18, and Dylan Klebold, 17, killed 12 students, a teacher and themselves April 20.

By Thursday, more than 1,100 of the school’s 1,500 students had signed the pledge, Green Mountain geography and sociology teacher Heather Beck said.