"BoxSize" command is a recent GuiXT feature

I am using SAP 4.6B and have modified transaction VA01 with Guixt. I now want to change the height of a box using boxsize. Isn't this function possible with GuiXT?

The "BoxSize" command is a recent GuiXT feature (summer 2002). Please download our latest version, and don't forget to copy guixt.dll and guixt.exe into the sapgui directory.