Sub and Function

declare [sub | function][name] : declare a subrutine/function in qbasic mode
sub [name](args...) : start a subrutine
exit sub : break a subrutine
end sub : terminate a subrutine

function [name](args...) : start a function
exit function : break a function
end function : terminate a function
return [value | variable] : set the result of a function(can substituite funcname=x)