Nearly 150 volunteers attended an orientation to take part today in a search for a seven-year-old San Diego girl. A helicopter was used earlier this week to search the Southern

California desert for Danielle van Dam. The seven-year-old vanished from her home after being put to bed a week ago last night.

There have been no arrests in connection with her disappearance.

San Diego police have concentrated during the past week on a neighbor of the missing girl, seizing his motor home and other belongings. The desert area has been the focus of the search because the neighbor said he drove his motor home there, the same day Danielle was reported missing.