>I have a grid witch accepts new entries. I need a way to check for double entries. Each entry needs to be unique or I get an error that the new record is cousing conflicts.

Jan Vantveer suggests a unique index on the grids table/cursor data source. You can [also] use a standard index and check (using INDEXSEEK) without moving the record pointer or using ON ERROR:

IF INDEXSEEK(lcCheckKey,.F.,'MyTableOrCursor','MyCheckKeyTag')
   * message the user and clear tyhe textbox
ELSE && Not there
   * accept entry as valid
ENDIF