We are all human and make mistakes. I KNOW that blank spaces are not allowed as a parameter name, but sometimes, I mis-type or forget to add a "-" or other character to fill in for the space. When I do this, I get a dialog that says "Unable to create parameter" and a "Cancel" button. Only choice I have is to click "Cancel" and lose everything I have entered. This is so lame. It has been this why since Inventor R4 and its time to change it. Make it a little more user friendly. I don't mean add a bunch of drop-downs or totally revamping the parameters dialog. Just a simply "OK" and then it returns back to where I was entering the name.

This is similar to James' idea posted here, but his is about the invalid characters in formulas, but the came concept....