yes no can be queried by using -1 for yes, 0 for no (-1 is the check mark, 0 is an unchecked value).
so if the search works for numeric value fields you should be able to adapt the code to deal with a yes/no field.
Probably in this section:
Code:
'Unfilter if there is no text to find, or no control to filter. Otherwise, filter.
If (strText = vbNullString) Or (strField = vbNullString) Then
frm.FilterOn = False
Else
'this section works for text fields only
'I would tend to look up the data type from the source table and build this statement accordingly BUT
'you could do something here for a specific field like:
if strfield = "YES NO FIELD NAME HERE" Then
frm.filter = strfield & " = " & if(strtext = "Yes", -1, 0)
else
frm.Filter = strField & " Like """ & IIf(mbcStartOfField, vbNullString, mstrcWildcardChar) & strText & mstrcWildcardChar & """"
endif
frm.FilterOn = True
End If