[Macluawn]

callbacks and functions aren't the same.
use

pawn Код:

FunctionName(parameters)
{
  return value;
}

or

pawn Код:

stock FunctionName(parameters)
{
  return value;
}

value equals the number (or array) you want to return. Use value as 1, if you dont need to return anything specific. Read on wiki the difference between stock functions and common functions