If you take the code you already posted:
openPrivButton( "hud_bg",32,0,138,7,5,-1,16,"" );
hug_bg = name of the button
32 = Left coordinate of the button (value between 0 and 200,0 is extreme left, 200 is extreme right)
0 = Top coordinate of the button (value between 0 and 200,0 is extreme top of screen, 200 is extreme bottom of screen)
138 = Width of the button (or how long is your button)
7 = Height of the button (or how deep is your button)
5 = Space between multiple lines of text displayed in the button
-1 = Duration the button is shown (-1 means that it stays on screen, until it is clicked)
16 = Colour of the button (* see below for more explanation)
"" = The Text displayed on the button
And then you can add one more value to a button, which is the name of the sub-routine you want to call, when someone clicks the button (this is optional)
So if you make something like this:
openPrivButton( "law_button",32,0,138,7,5,-1,16,"Read Law",Laws );
Sub Laws ( $KeyFlags, $id )
#Do something here to show the laws, starting by closing the button that just has been clicked
closePrivButton("law_button");
openPrivButton( "law_1",32,0,138,7,5,-1,16,"RTFM = Read the f*cking manual ;-)" );
EndSub
* Codes that can be used on button format:
0 - transparent button
16 - light button
32 - dark button
64 - align text to left
128 - align text to right
If you want to make a light colored button with text aligned to the left, combine the codes to one new code, for example 16+64 = 80