Trying to add value to calculated date field based on value in another field

[t]

We have the JIRA Misc fields plugin calculated date field. 

If the user chooses SLA1 on custom field 15401, for instance, I want the calcualtated date field (15402) to be current date +7 but clearly I'm doing something wrong and I'm stumped. Halp!

This is what i have:

<!-- @@Formula: 

if (issue.get("customfield_15401") == "SLA1")
return issue.get("customfield_15402").getTime() + 7);

else if (issue.get("customfield_15401") == "SLA2")
return issue.get("customfield_15402").getTime() + 14);

else if (issue.get("customfield_15401") == "SLA3")
return issue.get("customfield_15402").getTime() + 21);
-->

Thanks!

[t]

One other wrinkle I forgot to add: the Admin Helper on issues created with this field present is now missing the "Where is my field" option. It it's stead is an "Add field" option and when I attempt to add the field, it gives me a message telling me that I don't have permission to edit which is clearly false.  Strange