print "<p>base_url = $base_url\n";
$base_url = 'http://123.456.789.000';
print "<p>base_url = $base_url\n";

##</code><code>##

base_url = 
base_url = http://123.456.789.000

##</code><code>##

base_url = 
base_url = http://proxy.theirdomain.com:xxxx

##</code><code>##

print "<p>at A called_from = $called_from\n";
print "<p>at A base_url = $base_url\n";
@url_parts = split (/$base_url.*?\// ,$called_from);
print "<p>at B base_url = $base_url\n";
for $i (0 .. $#url_parts) {
	print "<br>url_parts[$i] = $url_parts[$i]\n";
}

##</code><code>##

at A called_from = http://123.456.789.000/mysubfolder/mypage.htm
at A base_url = http://123.456.789.000
at B base_url = http://123.456.789.000
url_parts[0] = 
url_parts[1] = mysubfolder/mypage.htm

##</code><code>##

at A called_from = http://proxy.theirdomain.com:xxxx/mysubfolder/mypage.htm
at A base_url = http://proxy.theirdomain.com:xxxx
at B base_url = http://proxy.theirdomain.com:xxxx
url_parts[0] = 
url_parts[1] =