How to invoke a Master page button click from a child page

I need to invoke a master page button click from a child page.
I tried tthe following which does not work. I see the alert pop up but the btnInvalidSession is not triggered

CHILD PAGE
If Session(":LoginID:") Is Nothing Then
                Dim btnInvalid As Button = CType(Page.Master.FindControl("btnInvalidSession"), Button)
                Dim val As String = btnInvalid.ClientID
                Dim msgDesc As String = "if (alert('Your session is no longer valid.\n\n Please login again.')) document.getElementById('" & val & "').click();"
                ScriptManager.RegisterClientScriptBlock(Me.Master, Me.Master.GetType(), "Invalid Session", msgDesc, True)
                Exit Sub        
               
            End If

MASTER PAGE - ASPX

<asp:Button ID="btnInvalidSession" runat="server" style="display:none;" OnClick="InvalidSessionButton_Click" />

MASTER PAGE - code behind

Protected Sub InvalidSessionButton_Click(ByVal sender As Object, ByVal e As System.EventArgs) Handles btnInvalidSession.Click
        Try
            Response.Redirect("login.aspx")
        Catch ex As Exception
            ex.ToString()
        End Try

    End Sub

CHILD PAGE
If Session(":LoginID:") Is Nothing Then
                Dim btnInvalid As Button = CType(Page.Master.FindControl("btnInvalidSession"), Button)
                Dim val As String = btnInvalid.ClientID
                Dim msgDesc As String = "if (alert('Your session is no longer valid.\n\n Please login again.')) document.getElementById('" & val & "').click();"
                ScriptManager.RegisterClientScriptBlock(Me.Master, Me.Master.GetType(), "Invalid Session", msgDesc, True)
                Exit Sub        
                
            End If

MASTER PAGE - ASPX

<asp:Button ID="btnInvalidSession" runat="server" style="display:none;" OnClick="InvalidSessionButton_Click" />

MASTER PAGE - code behind

Protected Sub InvalidSessionButton_Click(ByVal sender As Object, ByVal e As System.EventArgs) Handles btnInvalidSession.Click
        Try
            Response.Redirect("login.aspx")
        Catch ex As Exception
            ex.ToString()
        End Try

    End Sub

Select allOpen in new window