把第一个header()去掉,第二个header()里面写错了
<?php
header("Content-Type:image/jpg");
$image=imagecreate(300,80);
$bgcolor=imagecolorallocate($image,200,60,90);
$write=imagecolorallocate($image,0,0,0);
imagestring($image,5,80,30,"I Like PHP",$write);
imagejpeg($image);
imagedestroy($image);
?>