sub additem
{
    my $item = shift;
    my $quant = shift;
    die "You don't want any??  Shame!\n" unless $quant > 0;
    if(!(-e $custid)){
        open INF, ">$custid" or die "Couldnt create cart file: $!\n";
        print INF '';
        close INF;
    }

    open INF, "products.db" or die "Couldnt open db:$!\n";
    my @chosen = grep( /^$item\|/, <INF> );  # should return one line
    close INF;

    my ($itemno,$prod,$price,$desc) = split( /\|/, $chosen[0] );

    open CUSTCART, "$custid" or die "Couldnt read cart file: $!\n";
    my @custchoices = <CUSTCART>;
    close CUSTCART;

    for(@custchoices){
        chomp;
        my($in,$pr,$pri,$de,$qu) = split(/\|/,$_);
        if($in == $item){
            $qu += $quant;
            $quant = 0;  # this will signal that the item is already in the cart
            last;
        }
    }
    if ( $quant ) {  # this is a new item for the cart
        push @custchoices, join( "|", $itemno, $prod, $price, $desc, $quant );
    }

    open CUSTID, ">$custid" or die "Couldnt open personal cart: $!\n";
    print CUSTID @custchoices;
    close CUSTID or die "Couldnt close file: $!\n";
}