function IsCorrectIntegerValue(val:string):boolean;
var
 x:integer;
begin
 result:=true;
 for x:=1 to length(val) do 
  if s[x] in ['0'..'9']=false then
   begin
    if (x=1) and (s[x]='-') then continue;
    result:=false;
    break;
   end;
end;