Problem with function return datatype

Public Function Convert_barcode(ByVal s2 As String) As String
        Dim bcode As Integer
        If (s2.Length > 0) Then
            If s2.ToUpper Like "CA" Then
                bcode = -10
                Response.Write(bcode)
            End If
            If s2.ToUpper Like "PU" Then
                bcode = -15
                Response.Write(bcode)
            End If
            If Not ((s2.ToUpper Like "CA") Or (s2.ToUpper Like "PU")) Then
                bcode = CInt(s2)
            End If
        End If
        Return "bcode"
    End Function
 
"when returned to the calling sub procedure the bcode value is empty"
 
 
Protected Sub txtBarcode0_TextChanged(ByVal sender As Object, ByVal e As System.EventArgs) Handles txtBarcode0.TextChanged
        Convert_barcode(txtBarcode0.Text)
        txtBarcode0.Text = CStr(CInt(Session("bcode")))
        If (txtBarcode0.Text) = "-10" Then
            Exit Sub
        End If
        If (txtBarcode0.Text) = "-15" Then
            Exit Sub
        End If
        check_availability(txtBarcode0.Text)
        If CInt(Session("rtrnvalue")) = 0 Then
            lblbcodeerror.Visible = True
            txtBarcode0.Text = ""
        End If
    End Sub