Phone-a-Friend, a phone help line for latchkey children sponsored by the Virginia Cooperative Extension Service and ACTS (Action in the Community Through Service), gets underway today in Prince William County, Manassas and Manassas Park.

Between 3 p.m. and 7 p.m. children will be able to call 368-8069 and talk with a volunteer about whatever is on their minds.

According to a letter sent to area schools, Phone-a-Friend "is to be a supportive supplement to the family . . . to talk to when one's lonely, scared or just wants to share a thought."

About a dozen trained volunteers will staff the "warm-line," as it is called.

As school ends and many children in the area face long hours home alone this summer while parents work, the Extension Service has distributed thousands of brochures to students in grades four through eight.

The brochures stress that Phone-a-Friend is not meant for emergencies, and volunteer listeners will not give personal advice, recommend medication or "in any way advise the caller on how to deal with a personal problem other than referral" to an appropriate agency.

The program is similar to others in 44 states and Ontario.

The exact number of latchkey children in the county is unknown, but according to the Extension Service, in two-thirds of the county's households, both parents are employed outside the home.

School personnel have estimated that more than half of the county's students care for themselves after school.