php过滤函数 php下过滤HTML代码的函数

/*---------------------- 
过滤HTML代码的函数 
-----------------------*/ 
function htmlEncode($string) { 
  $string=trim($string); 
  $string=str_replace("&","&",$string); 
  $string=str_replace("'","'",$string); 
  $string=str_replace("&","&",$string); 
  $string=str_replace(""",""",$string); 
  $string=str_replace("\"",""",$string); 
  $string=str_replace("&lt;","<",$string); 
  $string=str_replace("<","<",$string); 
  $string=str_replace("&gt;",">",$string); 
  $string=str_replace(">",">",$string); 
  $string=str_replace("&nbsp;"," ",$string); 
  $string=nl2br($string); 
  return $string; 
}