there are three ways you can use
1. on the print button enter the code, assigning a where condition
' if value number
docmd.OpenReport "ReportName",,,"MyFieldInTable= " & me.combovalue
' if value text
docmd.OpenReport "ReportName",,,"MyFieldInTable= '" & me.combovalue & "'"
2. On the open event of the report you can assign the recordsource for the
report with the filter entered in the form
' For String
me.recordsource = "Select * From MyTable Where MyField = '" &
forms![FormName]![FieldName] & "'"
' For number
me.recordsource = "Select * From MyTable Where MyField = " &
forms![FormName]![FieldName]
3. Put the name of the combo from the form as the filter in recordsource of
the report
Select * From MyTable Where MyField = forms![formName]![FieldName]