The answer is probably no but let me ask anyway:

Is it possible to use a drop down list or a listbox for catgeories in Add Group wizard instead of Checkbox?

If no my second choice would be to make the Categories horizontal instead of vertical.

The categories are actually rendered using javascript. Using DropDown lists or list boxes are the probably the least user friendly option when you provide multiple selection options. A horizontal representation doesn't really work well with sub categories. You can still adjust the positioning and style with css.

I agree with you on Usabality Will but imagine a page with 100 categories and the scrolling a user will need. My first choice would have been ListBox so user can select multiple and with a scrollable fixed height listbox. I forgot about the sub-categories and I agree that won't work.

Thank you again. I am trying to launch my site by next week so I will keep dropping questions now and then and I appreciate all the quick responses.

You can wrap the categories in a scrolling div. That might give you the presentation you want.

Thanks WIll that is good idea. IT is not that important right now as I do not have that many categories but I hope it will grow and I can figure that out later.

Here's a quick way to get categories into a Horizontal View (not tested in all browsers yet):

#ulGroupCat {
padding-left:10px;
}

#ulGroupCat li {
display:block;
width:100%;
text-decoration:underline;
float:left;
clear:right;
padding:10px;
font-size:16px;
}

#ulGroupCat ul {
display:block;
padding:0 25px;
float:left;
width:100%;
}

#ulGroupCat ul li {
width:auto;
padding:0 4px;
text-decoration:none;
font-size:12px;
}

They could actually be templated quite easily if the subcategories were getting wrapped in the the category but it's actaully rendered outside like this: ul id="ulGroupCat" - li (cat) /li - ul (subcat) /ul - /ul

I'm still working on this, and will share my progress.

Here is a way to hide top level categories with css but keep lower level cats avail to select:

Thanks!