{
Initialize and check tag.
}      
procedure InitTag(var tag:Integer; name:String; typ:Integer);
begin
 tag:=FindTag(name);
 if (typ>0) and (TypeTag(tag)<>typ)
 then Trouble('Could not init tag: '+name);
 if (typ<0) and (TypeTag(tag)<>Abs(typ))
 then Problem('Could not init tag: '+name);
end;
