Hi I have this a userform where users enter data. first they enter a string of number into textbox4, and macro checks against the worksheet if this number exists. If it exists, then enable combobox3. if it does not exists and combobox2 selection is "Others", then disable combobox3. this is the code im using and I cant get it to work. Can anyone help please?

Private Sub TextBox4_Change()
    Dim frow
    
    If TextBox4.Text = "" Then
    TextBox5.Text = ""
    End If
    
    With Sheets("Sheet1")
        frow = Application.Match((TextBox4.Text), .Columns(1), 0)
        If IsError(frow) And ComboBox2.Value <> "Others" Then
        TextBox5.Text = ""
        CommandButton4.Enabled = True
        ComboBox3.Enabled = True
        
        End If
    End With
    
    With Sheets("Sheet1")
        frow = Application.Match((TextBox4.Text), .Columns(1), 0)
        If IsError(frow) And ComboBox2.Value = "Others" Then
        ComboBox3.Enabled = False
        
        End If
    End With
   
        
    
    
With Sheets("Sheet1")
        frow = Application.Match((TextBox4.Text), .Columns(1), 0)
        If Not IsError(frow) Then
        If .Cells(frow, 5).Value <> vbNullString And .Cells(frow, 7).Value = vbNullString Then
        TextBox5.Text = "Case is already in storage. Placed in " & .Cells(frow, 2).Value & " in Division " & .Cells(frow, 3).Value & " Box " & .Cells(frow, 4).Value & " by " & .Cells(frow, 5).Value & " on " & .Cells(frow, 6).Value: foundrow = frow
        CommandButton4.Enabled = False
        ComboBox1.Enabled = False
        ComboBox2.Enabled = False
        ComboBox3.Enabled = False
        ElseIf .Cells(frow, 12).Value <> vbNullString And .Cells(frow, 14).Value = vbNullString Then
        TextBox5.Text = "Case is already in storage. Placed in " & .Cells(frow, 9).Value & " in Division " & .Cells(frow, 10).Value & " Box " & .Cells(frow, 11).Value & " by " & .Cells(frow, 12).Value & " on " & .Cells(frow, 13).Value: foundrow = frow
        CommandButton4.Enabled = False
        ComboBox1.Enabled = False
        ComboBox2.Enabled = False
        ComboBox3.Enabled = False
        ElseIf .Cells(frow, 14).Value <> vbNullString Then
        TextBox5.Text = "Case returned by " & .Cells(frow, 14).Value & " on " & .Cells(frow, 15).Value: foundrow = frow
        CommandButton4.Enabled = False
        ComboBox1.Enabled = False
        ComboBox2.Enabled = False
        ComboBox3.Enabled = False
        Else
        TextBox5.Text = ""
        CommandButton4.Enabled = True
        ComboBox1.Enabled = True
        ComboBox2.Enabled = True
        ComboBox3.Enabled = True
        End If
        End If
    End With

    
End Sub