I am new to playbasic, though I've used other basic languages. Every time I try to use the Goto command I get an error "label Goto is not defined". Goto is one of the simplest commands in Basic, so I don't understand why I can't get it to work. I am using line numbers with it, e.g. Goto 15, but it gives me the error and won't even run the program.
That won't work as Line numbers don't exist in PlayBASIC, or the vast majority modern BASIC derivatives that I can think of. So Goto or Gosub expects a LABEL name to jump to. A Label is just named marker, that you can place where you want to goto or gosub into up/down the code. There's a few stylistic limitations with labels, namely they must be left justified. If it's not, it won't be seen as a label and you'll get an error. This prevents some (not all) of the really ugly usages some legacy coders seems set upon using..
[pbcode]
Goto MyLabel10
print "This line is being skipped by the Goto above"
MyLabel10:
print "End of program"
Sync
waitkey
[/pbcode]
See: PlayBASIC Manual / PlayBASIC documentation (http://www.playbasic.com/help.php)