一个解析URL及图片地址的JS函数

为BBS增加的解析函数，不知道有没有更好的方法，没看其它BBS的JS代码：

<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.0 Transitional//EN">
<HTML>
<HEAD>
<TITLE>BBS </TITLE>
<META NAME="Generator" CONTENT="EditPlus">
<META NAME="Author" CONTENT="">
<META NAME="Keywords" CONTENT="">
<META NAME="Description" CONTENT="">
<meta http-equiv="Content-Type" content="text/html; charset=gb2312"/>
<SCRIPT LANGUAGE="JavaScript">
<!--

function prints(str) {

var matchPIC = new RegExp("((?:http|https|ftp|mms|rtsp)://(&(?=amp;)|[A-Za-z0-9\./=\?%_~@#:;\+\-])+(gif|jpg|png))", "ig");
var matchURL = new RegExp("((?:http|https|ftp|mms|rtsp)://(&(?=amp;)|[A-Za-z0-9\./=\?%_~@&#:;\+\-])+)","ig");
var str2 ="";
str2 =str.replace(" "," ")
   if(matchPIC.test(str)){
        document.write(str2.replace(matchPIC, "<img src=\"$1\" hint=\"$1\"></img>"));
   }else{
          document.write(str2.replace(matchURL, "<a target=\"_blank\" href=\"$1\">$1</a>"));
   }
}
//-->
</SCRIPT>

</HEAD>

<BODY>
<SCRIPT LANGUAGE="JavaScript">
<!--
var str = "http://blogs.xmu.edu.cn/haohappy/archives/images/robot.jpg";
var str2 = "http://home.xmu.edu.cn/haohappy/bbs/mail.png";
var str3 = "http://www.csdn.net";

document.write("<BR>str为"+str+"<BR>处理后为：<BR>");
prints(str);
str = "";

document.write("<BR>str2为"+str2+"<BR>处理后为：<BR>");
prints(str2);
str2= "";

document.write("<BR>str3为"+str3+"<BR>处理后为：<BR>");
prints(str3);

//-->
</SCRIPT>
</BODY>
</HTML>