Drawing selection in sequence diagrams

I need to be able to draw selection in a sequence diagram. I have tried argou开发者_运维问答ml, visio, & visual paradigm to no avail :(

http://picasaweb.google.com/lh/photo/Q4ekN8j_9J4Xh0OYy4iQCw?authkey=Gv1sRgCJ_2mcXun4qbVA&feat=directlink

On the off chance "draw selection" means "model selection between alternatives", you need to add a alt combined fragment to the model. I don't know whether viso or argo support it ( argouml doesn't look promising), but visual paradigm appears to (how to guide).