Have you declared what tikking is in
'While (rst![ID] <> tikking)' and is ID the correct field to compare.
Also it will keep looping until it finds a match for <>tikking. If it reaches rst.EOF before finding a match, there will be no currect record, hence the error.
(Also, have you changed the recordsource of the form recently?. To be safe, remove the recordsource of the form, save it, reset the recordsource of the form and save it again.
Check that the table name is not a typo also)
If you are trying to find a particular record in the recordset, look up the findfirst method in help.
It would make life less confusing if your table was called tblTikking and your combo was called cboTikking. Not that this helps with your current problem...