In desktop version clicking a line and pressing "d" to add a dimension will bring up an input box to enter a number. Also double clicking an existing dimension brings up the same edit box. In both cases the desktop version highlights the default/existing value in the input box. The web version does not highlight the text, so you first need to delete whats there before typing something new. This is a pretty major annoyance when coming from the desktop version ;-)

We need to add code in guihtml.cpp to select the text in the edit box when we give it focus.