The Mount Horeb Area School District plans to host a school safety rally next Wednesday to honor the 17 victims of the mass shooting at Stoneman Douglas High School in Florida. The program is scheduled to last about 17 minutes.  Students, their parents and district staff members are all invited to take part, though parents who want to attend will have to complete a background check by Monday.  Students will be excused from their class on the day much of the country is holding a National School Walk Out to emphasize the need to stop school shootings.