use warnings is complaining

[Anonymous Monk]

Hi, i have written a script that reads some data and reports about it. Only when i use warnings i got the following complaint: 'Argument "" isn't numeric in printf at C:\Strawberry\codes\pack.pl line 11, <DATA> line 3.

Here's my code:

use strict;
#use warnings;
 
printf("%-11s %-27s %9s %11s","Date","Description","Incoming","Outgoin
+g\n");
my $x = 0;
my $tot;
my $totex;
while(<DATA>){
    if($x==0){$x++;next;}
my($date,$des,$inc,$exp)= unpack("A10 A27 A10 A*",$_);
    printf("%-10s %-27s %10.2f %10.2f\n",$date,$des,$inc,$exp);
    $tot += $inc;
    $totex += $exp;
}
printf("%38s %10.2f %10.2f","Totals",$tot,$totex);



__DATA__
Date       Description                incoming     outgoing
01/24/2001 Zed's Camel Emporium         100.00      1147.99
01/28/2001 Flea spray                                 24.99
01/29/2001 Camel rides to tourists      235.00             
01/31/2001 avage1                       125.00                      
01/20/2001 carpe diem                    20.00        23.00

How can i get rid of this, besides from turning warnings off?