Create a new label in AX 7

Hi,

In AX 7, I added a new label file by

From VS solution -> Add new Item -> Labels And Resources -> Label File. In the Label file wizard, I specified Label file ID as LUKA, and click Next, and I add EN-US, JA as the Selected languages.

I can see two label files created in my VS solution. When I tried to add a new label by double clicking the label files, and I click New button on the form, the label ID became NewLabel2 instead of @LUKA1, even I changed it to @LUKA1, I cannot save it.

Do I miss some steps here?

Thanks,