Dialog_Tab...

Hi,
I find this dialog very unintuitive:
1. What is Default tab stop? (I think tabs equally distributed with
    this measurement)
2. User-defined Tabs: I have no tabs defined and the dialog tells me
    to 'add' something (I know the default-tab)
    => this is not what I need
    I know at which position I want a tabstop but I cant enter that:

So I cam to an other design... look at attachment.
(This is a fast design study) I would implement if desired...

Michael Rosenbruch