I am using Zoho Tasks

http://tasks.zoho.com/biz/taskindex.do

When I create a new Task, I want to assign to a particular user

user is mathi.dbx created under zoho crm 

But when I click Assigned To I am unable to find mathi.dbx to assign the task. Also I find no option to add the user.

Please let me know how do  I add new user under assigned to?

Cheers

-Jag