Autopopulate firstname and lastname in generated form

[Amar]

I have a field name called username in that who ever login and start the form it should autopopulate there firstname + lastname it should be done in generated form — not from embedded form
please anyone know help me

[Niall]

Can you show your forms?
it would usually autopopulate.

[Amar]

In the originator it should autopopulate the firstname + lastname