Use one box on another form.

Use one box on another form.


First of all, I hope you understand me, because I'm from mexico and my English is very limited.

I am trying to send emails through automated 3 different forms 

-Clientes
-Ordenes
- Articulos 

The form "Clientes" contains a box with an email and it's easy to create an automatic email., But "Orders" and "Articles" contains "Email" and would spend much time repeating 3 times the box. 

I wonder if Link "Email" with the other 2 forms possible. 

This is what I try,but I have an error:

void sendnotification(Clientes1 EmailCliente)
{
Email  =  clientes1  [Email];
EmailCliente  =  Clientes1  [Order_Relationship == Email.mail];
    sendmail
    (
        To       : EmailCliente.Email
        From     :  zoho.adminuserid
        Subject  :  "Confirmation"
        Message  :  "Su orden Ha sido adquirida de Manera Exitosa"
    )
}
        )
    }
}

I tried many things but I have had many errors mainly "'Email' is not of type Lookup and reference form fields can not access" or "Form Clientes1 does not belong to this application."

I would appreciate anyone who could help me with this, I took 3 days without doing anything about it.