(PHP 4, PHP 5)
eregi_replace — Replace regular expression case insensitive
This function was DEPRECATED in PHP 5.3.0, and REMOVED in PHP 7.0.0.
Alternatives to this function include:
PCRE_CASELESS)
      modifier)
    $pattern
   , string $replacement
   , string $string
   )This function is identical to ereg_replace() except that this ignores case distinction when matching alphabetic characters.
patternA POSIX extended regular expression.
replacement
       If pattern contains parenthesized substrings,
       replacement may contain substrings of the form
       \digit, which will be
       replaced by the text matching the digit'th parenthesized substring; 
       \0 will produce the entire contents of string.
       Up to nine substrings may be used. Parentheses may be nested, in which
       case they are counted by the opening parenthesis.
      
stringThe input string.
   The modified string is returned. If no matches are found in 
   string, then it will be returned unchanged.
  
Example #1 Highlight search results
<?php
$pattern = '(>[^<]*)('. quotemeta($_GET['search']) .')';
$replacement = '\\1<span class="search">\\2</span>';
$body = eregi_replace($pattern, $replacement, $body);
?>