Easiest way to totally prevent it is to set an no duplicates index on the
SignInDte field.
Of course, if you want to do this BY USER you will need to make a multi-field
unique index based on the userid and SignInDte field.
To create a multiple field unique index (Compound index)
--Open up the table in design mode
--Select View: Index from the menu
--Enter a name for the iIndex in first row under Index Name
--Select one field in the index under Field Name
--Set Unique to Yes
--Move down one line and select the next FieldName
(Do NOT skip rows, do NOT enter the index name again)
--Continue moving down and selecting fieldnames until all needed fields are
included.
--Close the index window and close and save the table
John Spencer
Access MVP 2002-2005, 2007-2010
The Hilltop Institute
University of Maryland Baltimore County