Enterprise Portal: Save and Close button

Hi!

I want to disable the "Save and Close" button on the Sales order form (Enterprise Portal), after the first click.

Beacuse, When creating a sales order in the EP and clicking "save and close" more than once, the system opens as many sales orders as you clicked the button "save and close".

For example: by clicking 5 times "save and close" the EP creates 5 identical sales orders!!

Any ideas?

Thanks!