Lock size of Edit Object

Hi there!
I am trying to lock the size of an edit box within my frame. I have set the code to Always Set Horizontal Size to 309, Set Vertical Size to 73.

This works to an extent. However, the user is still able to pull the resize tab in the bottom right corner. The box flashes as it resizes then jumps back to the commanded size.

Is there a way to completely disable the sizing function? Or to hide the resizing tab? Photo attached.

Attachment 15281

Thanks!