Surpress system message

After adding an AR-Invoice, two seperate system-messages appears in the window, one about a good receipt which has not been issued and one about not changing the document after adding the form. Both messages can be answered by yes or no. For the workflow, both system messages may be answered with yes, or better we don'' t need these messages. I there a way to shut them down automatically or even to surpress the system messages?

Thanks,

Freek