Subscript error when finding next blank row in added worksheet

[bostenson]

I want to find the next blank row in a newly added worksheet but I have a subscript out of range error in line WSNr = Worksheets(i).Cells(Rows.Count, "A").End(xlUp).Row + 1. This is the complete code:

Private Sub cmdSaveGL_Click()

    Dim WSNr As Long
    
    Dim a As Integer
    Dim i As Long
    a = ThisWorkbook.Worksheets.Count
        
' Find next blank row


    WSNr = Worksheets(i).Cells(Rows.Count, "A").End(xlUp).Row + 1
                
' Add Expense data to Registers


    If Me.cmbGLCategory.value = "Expense" Then
        For i = 1 To a
            If Worksheets(i).Name = cmbGLCashAcct.value Then
                Worksheets(i).Range("A" & WSNr).value = Me.txbGLName.value
            End If
        Next
    End If    

End Sub

What am I missing in my code in order to find the blank row in the new sheet? Thanks in advance.


- Ben