How do I pull a Dimension centerline in a Detail View

[nsinha73]

I am using detail view to to do some 2D Details....Everything is great except when I wanna dimension fro "Center"
How do you guys do it?

[robert_taylor]

add a centerline to the center of your object

[nsinha73]

lol!!! I now realize that my question sounded kinda stupid....lol!! Thanks anyway