function ubb($str) {
$color=Array('red','blue','green');
$str=eregi_replace('\[url\]([a-zA-Z0-9@:%_.~#-\?&]+)\[\/url\]','<a href=http://\\1>\\1</a>',$str);//url
$str=eregi_replace('\[url=http://([a-zA-Z0-9@:%_.~#-\?&]+)\](.+)\[\/url\]','<a
href=\\1 target=_blank>\\2</a>',$str);
$str=eregi_replace('\[url=([a-zA-Z0-9@:%_.~#-\?&]+)\](.+)\[\/url\]','<a
href=http://\\1 target=_blank>\\2</a>',$str);
$str=eregi_replace('\[img\]([a-zA-Z0-9@:%_.~#-\?&]+)\[\/img\]','<img src=http://\\1>\\1</img>',$str);//img
$str=eregi_replace('\[h([1-6])\](.+)\[\/h[1-6]\]','<h\\1>\\2</h\\1>',$str);//h1-6
$str=eregi_replace('\[email\]([_\.0-9a-z-]+@([0-9a-z][0-9a-z-]+\.)+[a-z]{2,3})\[\/email\]','<a
href=mailto:\\1>\\1</a>',$str);//email
$str=eregi_replace('\[email=([_\.0-9a-z-]+@([0-9a-z][0-9a-z-]+\.)+[a-z]{2,3})\](.+)\[\/email\]','<a
href=mailto:\\1>\\2</a>',$str);
$str=eregi_replace('\[b\](.+)\[\/b\]','<b>\\1</b>',$str);
$str=eregi_replace('\[i\](.+)\[\/i\]','<i>\\1</i>',$str);
$str=eregi_replace('\[size=(.+)\](.+)\[\/size\]','<font size=\\1>\\2</font>',$str);
$str=eregi_replace('\[color=(.+)\](.+)\[\/color\]','<font color=\\1>\\2</font>',$str);
$str=eregi_replace('\[sub\](.+)\[\/sub\]','<sub>\\1</sup>',$str);//下裱
$str=eregi_replace('\[sup\](.+)\[\/sup\]','<sup>\\1</sup>',$str);//上标
for($i=0;$i<=count($color);$i++)$str=eregi_replace('\['.$color[$i].'\](.+)\[\/'.$color[$i].'\]','<font
color='.$color[$i].'>\\1</font>',$str);
$str=preg_replace("/\[quote\](.+?)\[\/quote\]/is","<blockquote><font
size='1' face='Courier
New'>quote:</font><hr>\\1<hr></blockquote>",
$str);
$str=preg_replace("/\[code\](.+?)\[\/code\]/is","<blockquote><font
size='1' face='Times New Roman'>code:</font><hr
color='lightblue'><i>\\1</i><hr
color='lightblue'></blockquote>", $str);
$str=preg_replace("/\[sig\](.+?)\[\/sig\]/is","<div
style='text-align: left;color: darkgreen;margin-left:
5%'><br><br>--------------------------<br>\\1<br>--------------------------</div>",
$str);
return $str;
}