/*
  Replacing URL matches
*/
$txt = eregi_replace('([[:space:]]|^)(www)', '\\1http://\\2', $txt);
$prefix = '(http|https|ftp|telnet|news|gopher|file|wais)://';
$pureUrl = '([[:alnum:]/\n+-=%&:_.~?]+[#[:alnum:]+]*)';
$txt = eregi_replace($prefix . $pureUrl, '<a href="\\1://\\2" target="_blank">\\1://\\2</a>', $txt);

/*
  Replacing E-mail addresses
*/
$txt = eregi_replace('([0-9a-z]([-_.]?[0-9a-z])*@[0-9a-z]([-.]?[0-9a-z])*\\.[a-wyz][a-z](fo|g|l|m|mes|o|op|pa|ro|seum|t|u|v|z)?)', '<a href="mailto:\\1">\\1</a>', $txt);