note 11561 added to ereg_replace

I've been trying to, after a search, place "<span class=classname>$string</span>" I can do that easily enough but the problem is it replaces that $string is also replaced inside other markers. eg : if $string = "image"; then it also makes <IMG SRC=images/name.gif> into <IMG SRC=<span>image</span>s/name.gif> I tried playing around with ereg_replace but could only come up with the following $rep = "a|e|!"; $newstring = eregi_replace(">([^<>]*)($rep)([^<>]*)<", ">\\1<b>\\2</b>\\3<", "<>a asdf asdf a a<asdf asdf asdf>h>el<l>o!!!<asdf asd f>"); print $newstring; This puts bold anything in $rep but only seems to do it to the last instance. For example it will only make bold the 3rd 'a' in the string as well as the 'e' and the third '!'. Can anyone help me?! http://www.php.net/manual/en/function.ereg-replace.php