>I wish to make labels by programming (RDC).
>I want to thus change the height of detail, the number of column....
>How must I make because the properties detailHeight , detailWidth , HorizontalGap are read Only ?

Bernhart,

You may want to search Crystal's knowledge base on this. I did a quick search on labels and found the following which may or may not be of help to you:

http://support.crystaldecisions.com/library/kbase/articles/c2008863.asp

Either way, it might lead you on the right path.

Laterness,
Jon