Sinclair QL

Programming
30
proc getnum; m$,min,max
rem ***** get number in range *****
local wrong
let _rong=1
whi le wrong
print m$; "? II;
error readnum
let wrong=errnumO
if not wrong
if num<min or num>max
let wrong=1
print "Allowed range ;s ";min;" to ";max
endif
endif
if wrong
print "Try again"
end if
endwhi le
endproc
Since error must be followed by the name of a procedure. we define readnum to input
a value
for the vanable num.
proc readnum
input num
endprac
Suppose you want a procedure thaf checks that a number is within the range 1 to 10
You can do this uSing getnum in the following way:
prac check
getnum; "Numeric value?",1,10
endproc
12/S-l