put a default value in the description field for a specific project and for a specific issue type

[amit kertes]

hi 
my issue is regarding the description field 
i use the guide to put a default value in the description field
https://confluence.atlassian.com/jira060/setting-a-default-value-in-the-description-field-370705080.html\\ and its work great
but my problem is that i need it only for a specific project and for a specific issue type in this p[roject and not to all projects and all issue type
can u please help me and tell me how i can do this 
can i add "IF ==XX " in this script ??