老师：这代码在我电脑上打不出验证码，不知是原因在那里，我是个新，不懂语言。

<?php 

require_once 'string.func.php';

//通过GD库做验证码

function verifyImage($type=1,$length=4,$pixel=0,$line=0,$sess_name = "verify"){

session_start();

//创建画布

$width = 80;

$height = 28;

$image = imagecreatetruecolor ( $width, $height );

$white = imagecolorallocate ( $image, 255, 255, 255 );

$black = imagecolorallocate ( $image, 0, 0, 0 );

//用填充矩形填充画布

imagefilledrectangle ( $image, 1, 1, $width - 2, $height - 2, $white );

$chars = buildRandomString ( $type, $length );

$_SESSION [$sess_name] = $chars;

//$fontfiles = array ("MSYH.TTF", "MSYHBD.TTF", "SIMLI.TTF", "SIMSUN.TTC", "SIMYOU.TTF", "STZHONGS.TTF" );

$fontfiles = array ("SIMYOU.TTF" );

//由于字体文件比较大，就只保留一个字体，如果有需要的同学可以自己添加字体，字体在你的电脑中的fonts文件夹里有，直接运行输入fonts就能看到相应字体

for($i = 0; $i < $length; $i ++) {

$size = mt_rand ( 14, 18 );

$angle = mt_rand ( - 15, 15 );

$x = 5 + $i * $size;

$y = mt_rand ( 20, 26 );

$fontfile = "../fonts/" . $fontfiles [mt_rand ( 0, count ( $fontfiles ) - 1 )];

$color = imagecolorallocate ( $image, mt_rand ( 50, 90 ), mt_rand ( 80, 200 ), mt_rand ( 90, 180 ) );

$text = substr ( $chars, $i, 1 );

imagettftext ( $image, $size, $angle, $x, $y, $color, $fontfile, $text );

}

if ($pixel) {

for($i = 0; $i < 50; $i ++) {

imagesetpixel ( $image, mt_rand ( 0, $width - 1 ), mt_rand ( 0, $height - 1 ), $black );

}

}

if ($line) {

for($i = 1; $i < $line; $i ++) {

$color = imagecolorallocate ( $image, mt_rand ( 50, 90 ), mt_rand ( 80, 200 ), mt_rand ( 90, 180 ) );

imageline ( $image, mt_rand ( 0, $width - 1 ), mt_rand ( 0, $height - 1 ), mt_rand ( 0, $width - 1 ), mt_rand ( 0, $height - 1 ), $color );

}

}

header ( "content-type:image/gif" );

imagegif ( $image );

imagedestroy ( $image );

}

这代码能在我电脑上打出验证码，登陆不了，显示验证码错。

<?php

require_once 'string.func.php';

//通过GD库做验证码

function verifyImage($type=1,$length=4,$pixel=0,$line=0,$sess_name = "verify"){

 session_start();

//创建画布

$width=80;

$height=28;

$image=imagecreatetruecolor($width,$height);

$white=imagecolorallocate($image,255,255,255);

$black=imagecolorallocate($image,0,0,0);

// 用填充矩形填充画布

imagefilledrectangle($image,1,1,$width-2,$height-2,$white);

$chars=buildRandomString($type,$length);

$sess_name="varify";

$_SESSION[$sess_name]=$chars;

$fontfiles=array("MSYH.TTF","MSYHBD.TTF","SIMHEI.TTF","SIMKAI.TTF","SIMSUN.TTC"); 

for($i=0;$i<$length;$i++) {

    $size=mt_rand(14,18);

    $angle=mt_rand(-15,15);

    $x=5+$i*$size;

    $y=mt_rand(20,26);

    $fontfile="../fonts/".$fontfiles[mt_rand(0,count($fontfiles)-1)];

    $text=substr($chars,$i,1);

    $color=imagecolorallocate($image,mt_rand(50,90),mt_rand(80,200),mt_rand(90,180));

    imagettftext($image,$size,$angle,$x,$y,$color,$fontfile,$text);

}

if ($pixel) {

for($i = 0; $i < 50; $i ++) {

imagesetpixel ( $image, mt_rand ( 0, $width - 1 ), mt_rand ( 0, $height - 1 ), $black );

}

}

if ($line) {

for($i = 1; $i < $line; $i ++) {

$color = imagecolorallocate ( $image, mt_rand ( 50, 90 ), mt_rand ( 80, 200 ), mt_rand ( 90, 180 ) );

imageline ( $image, mt_rand ( 0, $width - 1 ), mt_rand ( 0, $height - 1 ), mt_rand ( 0, $width - 1 ), mt_rand ( 0, $height - 1 ), $color );

}

}

header ( "content-type:image/gif" );

imagegif ( $image );

imagedestroy ( $image );

}