图片上增加文字

<?php
//图片上增加文字
function createpic($width,$height,$string){
	$im = imagecreate($width, $height);
	$bgcolor = imagecolorallocate($im,255, 255, 255);
	$text_color = imagecolorallocate($im,0,0,0);
	imagestring($im,5,5,5,$string,$text_color,);
	imagejpeg($im,'text.jpg');
	imagedestroy($im);}

createpic(300,150,'hello world');