关于GD模块的入门问题[求助]

关于GD模块的入门问题[求助]
程序如下：
#!/usr/bin/perl -w

use GD;
$gd=GD::Image->new(400,300);

$white=$gd->colorAllocate(255,255,255);
$black=$gd->colorAllocate(0,0,0);
$red=$gd->colorAllocate(255,0,0);
$green=$gd->colorAllocate(0,255,0);
$blue=$gd->colorAllocate(0,0,255);
$yellow=$gd->colorAllocate(255,255,0);

$gd->filledRectangle(0,129,199,169,$blue);

my $poly = GD::Polygon->new();
$poly->addPt(199, 149);
$poly->addPt(399, 74);
$poly->addPt(324, 149);
$poly->addPt(399, 224);
$gd->filledPolygon($poly, $yellow);
$gd->polygon ($poly, $black);

$gd->arc(199, 149, 250, 250, 0, 360, $red);
$gd->arc(199, 149, 100, 200, 0, 360, $red);
$gd->fillToBorder(99, 149, $red, $green);
$gd->rectangle(0, 0, 399, 299, $red);
$gd->line(199, 0, 199, 299, $red);
$gd->line(0, 149, 399, 149, $red);

运行没有问题但是就是没有出图片，请问这是为什么？谢谢啦

难道就没有人知道？？？？.
难道就没有人知道？？？？

哎，我自己回答吧，昨天被.
哎，我自己回答吧，昨天被我搞出来了，在最后加上：
binmode MYOUTFILE;
print MYOUTFILE $gd->png;
就可以了。