The Joplin Board of Education will be asked tonight to support an expansion of the school district’s early childhood education center. The early childhood program is housed in trailers on the McKinley Elementary School campus and enrolls about 250 children. Administrators will recommend that the district construct a separate building for the program — estimated to cost between $9.5 million and $14.5 million — that could encourage enrollment of up to 600 students, according to documentation from the district.