Adding record to table based on combo box selection

I am just getting my feet wet in Access. I have two tables and one form. In the form I have a combo box which holds selections from one table. I would like users to be able to choose a selection from the combo box the enter a entry in the following field. When clicking save I would like this field plus the ID of the item selected in the combo box stored in a table.

I am attaching an example as it is far easier to show than explain. Any help would be greatly appreciated.

Thank You!

I am using Access 2007

Here is the code for adding a record to the table just try this may be helpful for you..

Private Sub AddTaskBttn_Click()
Dim Sn As String
Sn = Me.cmbSerialNumber.Column(0)
DoCmd.SetWarnings False
DoCmd.RunSQL "Insert Into Tasklist( SerialNumber ) Select '" & Sn & "' As Expr;"
DoCmd.SetWarnings True
DoCmd.OpenForm "Task", , , "Dockets.SerialNumber =" & "'" & Me.cmbSerialNumber.Column(0) & "'", acFormAdd

End Sub

On the Form Open of Task I have the following code

P

rivate Sub Form_Open(Cancel As Integer)
If Not IsNull(Me.OpenArgs) Then
Sn.Value = Me.OpenArgs
Me.Requery
End If
End Sub

On the task form I have the following save and close button

Private Sub FormClose_Click()
On Error GoTo Err_FormClose_Click
DoCmd.Save
DoCmd.Close
Exit_FormClose_Click:
Exit Sub
Err_FormClose_Click:
MsgBox Err.Description
Resume Exit_FormClose_Click
End Sub