[NTG-context] making my own simpleslides module

[dalyoung]

Dear Woldgang and Marco,

Thank you for your correction.

It works after bracing the \externalfigure command.
Now, I have to modify the numbers of header, footer, etc to make my style.

I also change the order of  "\setupexternalfigure[directory=...]" and "\usemodule[simpleslides]..." to apply the relational position.

Now, I don't have to keep two mode "my own" and "simple slides". Instead, I just use "simpleslides-s-myown".

Thank you again.

Best regards,

Dalyoung