How to insert Caller name in Incident template

[Kazu4]

Id like to create incident template for contacting customers.

I want to insert customers name in "Additional comments" automatically,
so entered as below,

javascript:"Dear "+gs.current.caller_id.LastName()

but the result is "Dear undefined".

How can I insert caller user name of current incident?

[Eugene T]

Hi

So i added 

javascript:"Dear "+gs.getUserDisplayName()

However it does NOT bring back Caller name. It does populate current AGENT name who is applying reply template. 

Is there really a way to populate actual Caller name ? Person who summitted the ticket. 

[Kieran Anson · Accepted solution]

gs.getUserDisplayName is based off the current logged in user, not fields on the form. As provided previously, your only option for this is Response Templates rather than the classic templates.