help with runtime error

[rnero]

I keep getitng this 2001 - You canceled the previous operation.
Some one please help me.
Here is the code.

Option Compare Database
Option Explicit

Private Sub cboColumnField_AfterUpdate()

Dim strSQL As String
Dim strSQLSF As String

cboNumericField = Null

strSQL = " SELECT DISTINCT tblDemo.NumericField FROM tblDemo "
strSQL = strSQL & " WHERE tblDemo.RowField = '" & cboRowField & "' And "
strSQL = strSQL & " tblDemo.ColumnField = '" & cboColumnField & "'"
strSQL = strSQL & " ORDER BY tblDemo.NumericField;"

cboNumericField.RowSource = strSQL

strSQLSF = " SELECT * FROM tblDemo "
strSQLSF = strSQLSF & " WHERE tblDemo.RowField = '" & cboRowField & "' And "
strSQLSF = strSQLSF & " tblDemo.ColumnField = '" & cboColumnField & "'"


Me!sfrmForm.LinkChildFields = ""
Me!sfrmForm.LinkMasterFields = ""

Me!sfrmForm.LinkChildFields = "RowField;ColumnField"
Me!sfrmForm.LinkMasterFields = "RowField;ColumnField"
Me.RecordSource = strSQLSF
Me.Requery

End Sub

Private Sub cboNumericField_AfterUpdate()

Dim strSQLSF As String

strSQLSF = " SELECT * FROM tblDemo "
strSQLSF = strSQLSF & " WHERE tblDemo.RowField = '" & cboRowField & "' And "
strSQLSF = strSQLSF & " tblDemo.ColumnField = '" & cboColumnField & "' And "
strSQLSF = strSQLSF & " tblDemo.NumericField = " & cboNumericField

Me!sfrmForm.LinkChildFields = ""
Me!sfrmForm.LinkMasterFields = ""

Me!sfrmForm.LinkChildFields = "RowField;ColumnField;NumericField"
Me!sfrmForm.LinkMasterFields = "RowField;ColumnField;NumericField"
Me.RecordSource = strSQLSF
Me.Requery

End Sub

Private Sub cboRowField_AfterUpdate()

Dim strSQL As String
Dim strSQLSF As String

cboColumnField = Null
cboNumericField = Null

strSQL = "SELECT DISTINCT tblDemo.ColumnField FROM tblDemo "
strSQL = strSQL & " WHERE tblDemo.RowField = '" & cboRowField & "'"
strSQL = strSQL & " ORDER BY tblDemo.ColumnField;"

cboColumnField.RowSource = strSQL

strSQLSF = "SELECT * FROM tblDemo "
strSQLSF = strSQLSF & " WHERE tblDemo.RowField = '" & cboRowField & "'"

Me!sfrmForm.LinkChildFields = "RowField"
Me!sfrmForm.LinkMasterFields = "RowField"
Me.RecordSource = strSQLSF
Me.Requery

End Sub

Private Sub cmdShowAll_Click()
On Error GoTo err_cmdShowAll_Click

cboRowField = Null
cboColumnField = Null
cboNumericField = Null
Me!sfrmForm.LinkChildFields = ""
Me!sfrmForm.LinkMasterFields = ""
Me.RecordSource = "tblDemo"
Me.Requery

exit_cmdShowAll_Click:
Exit Sub

err_cmdShowAll_Click:
MsgBox Err.Description
Resume exit_cmdShowAll_Click

End Sub

Private Sub Form_Open(Cancel As Integer)

Dim strSQL As String

strSQL = " SELECT DISTINCT tblDemo.RowField FROM tblDemo ORDER BY tblDemo.RowField;"
cboRowField.RowSource = strSQL

End Sub