Looping through form controls and updating their properties

Howdy Folks,

After a bit of searching I can't quite find a clear answer so thought I would ask the question (probably again, so apologies).

I have written a function that is intending to loop through the controls on a form to replace apostrophes with a safe version to aid with dynamic sql production (the sql bit isn't important, just context)

so here is the function:

    Public Sub TextBoxQuotes(ByVal Parent As Object)
        Dim c As Control
        For Each c In Parent.Controls
            If c.HasChildren Then
                TextBoxQuotes(c)
            Else
                If TypeOf (c) Is TextBox Then
                    c.Text.Replace(Chr(39), Chr(96)) 'replace ' with `
                End If
            End If
        Next
    End Sub

Tracing through a run, the function is entered into and will step in correctly but the replace doesn't seem to do anything. I assume this is some schoolboy error on my part! I have tried ByRef and ByVal to no change and have wondered if i am somehow creating an instance of the control instead of actually updating the original.

Can anyone see why the replace isn't doing anything?

Any help would be appreciated