Franklin County yesterday became the fifth county to endorse a riverboat gambling proposal. Webster County is among the next counties to consider the idea. Webster County supervisors on Tuesday set the date of March 23rd for a special election on the issue of legalized gambling on a casino boat near Fort Dodge. The petition was presented last week requesting the election. It would have to pass by a simple majority but would also need the state racing and gaming commission to lift its moratorium on new gambling licenses.