String.Replace not working [Resolved]

In the code below, the .Replace function appears to run w/o error when I step through the code, but it doesn't replace the string. The original string is left intact. What's going wrong? Thanks.

VB Code:

Private Sub SetQuestionSql(ByVal cb As CheckBox)
        Select Case cb.Name
            Case "cbModule"
                If cb.Checked = True Then
                    If mblnChanged Then
                        mstrQuestionSQL &= " AND modcode = "
                    Else
                        mstrQuestionSQL &= " WHERE modcode =  "
                        mblnChanged = True
                    End If
                Else
                    If mstrQuestionSQL.IndexOf("AND modcode = ") <> -1 Then
                        mstrQuestionSQL.Replace("AND modcode = ", "")
                    Else
                        mstrQuestionSQL.Replace("WHERE modcode = ", "")
                    End If
                End If

mstrQuestionSQL = mstrQuestionSQL.Replace("AND modcode = ", "")

Replace is a function that returns the result. You still have 6o apply that change to the string.

Duh! :blush: Thanks!