credit_cash_check/views/account_invoice_view.xml

<?xml version="1.0" encoding="utf-8"?>
<openerp>
    <data>
        <record id="account_invoice_customer_credit" model="ir.ui.view">
            <field name="name">account.invoice.credit</field>
            <field name="model">account.invoice</field>
            <field name="inherit_id" ref="account.invoice_form" />
            <field name="arch" type="xml">
              <field name="payment_term" position="replace"/>
              <field name="account_id" position="after">
                <label for="contado" string="Forma de pago"/>
                <div>
                  <label for="contado" string="Contado"/>
                  <field name="contado" attrs="{'readonly': [('state','!=','draft')]}"/>

                  <label for="credito" string="Crédito"/>
                  <field name="credito" attrs="{'readonly' : ['|',('state','!=','draft')]}"/>

                  <field name="payment_term" options="{'no_create': True}" attrs="{'invisible' : [('credito', '=', False )]}"/>

                </div>
              </field>
            </field>
        </record>

        <record id="account_invoice_supplier_credit" model="ir.ui.view">
                    <field name="name">account.invoice.supplier.credit</field>
                    <field name="model">account.invoice</field>
                    <field name="inherit_id" ref="account.invoice_supplier_form" />
                    <field name="arch" type="xml">
                      <field name="payment_term" position="replace"/>
                      <field name="journal_id" position="after">
                        <label for="contado" string="Forma de pago"/>
                        <div>
                          <label for="contado" string="Contado"/>
                          <field name="contado" attrs="{'readonly': [('state','!=','draft')]}"/>

                          <label for="credito" string="Crédito"/>
                          <field name="credito" attrs="{'readonly' : ['|',('state','!=','draft')]}"/>

                          <field name="payment_term" options="{'no_create': True}" attrs="{'invisible' : [('credito', '=', False )]}"/>

                        </div>
                      </field>

                    </field>
                </record>
    </data>
</openerp>