function DeleteHtml($str)
{
/*$str=preg_replace("/\s+/", " ", $str); //過濾多余回車
$str=preg_replace("/<[ ]+/si","<",$str); //過濾<__("<"號后面帶空格)
$str=preg_replace("/<\!--.*?-->/si","",$str); //注釋
$str=preg_replace("/<(\!.*?)>/si","",$str); //過濾DOCTYPE
$str=preg_replace("/<(\/?html.*?)>/si","",$str); //過濾html標簽
$str=preg_replace("/<(\/?head.*?)>/si","",$str); //過濾head標簽
$str=preg_replace("/<(\/?meta.*?)>/si","",$str); //過濾meta標簽
$str=preg_replace("/<(\/?body.*?)>/si","",$str); //過濾body標簽
$str=preg_replace("/<(\/?link.*?)>/si","",$str); //過濾link標簽
$str=preg_replace("/<(\/?form.*?)>/si","",$str); //過濾form標簽
$str=preg_replace("/cookie/si","COOKIE",$str); //過濾COOKIE標簽
$str=preg_replace("/<(applet.*?)>(.*?)<(\/applet.*?)>/si","",$str); //過濾applet標簽
$str=preg_replace("/<(\/?applet.*?)>/si","",$str); //過濾applet標簽
$str=preg_replace("/<(style.*?)>(.*?)<(\/style.*?)>/si","",$str); //過濾style標簽
$str=preg_replace("/<(\/?style.*?)>/si","",$str); //過濾style標簽
$str=preg_replace("/<(title.*?)>(.*?)<(\/title.*?)>/si","",$str); //過濾title標簽
$str=preg_replace("/<(\/?title.*?)>/si","",$str); //過濾title標簽
$str=preg_replace("/<(object.*?)>(.*?)<(\/object.*?)>/si","",$str); //過濾object標簽
$str=preg_replace("/<(\/?objec.*?)>/si","",$str); //過濾object標簽
$str=preg_replace("/<(noframes.*?)>(.*?)<(\/noframes.*?)>/si","",$str); //過濾noframes標簽
$str=preg_replace("/<(\/?noframes.*?)>/si","",$str); //過濾noframes標簽
$str=preg_replace("/<(i?frame.*?)>(.*?)<(\/i?frame.*?)>/si","",$str); //過濾frame標簽
$str=preg_replace("/<(\/?i?frame.*?)>/si","",$str); //過濾frame標簽
$str=preg_replace("/<(script.*?)>(.*?)<(\/script.*?)>/si","",$str); //過濾script標簽
$str=preg_replace("/<(\/?script.*?)>/si","",$str); //過濾script標簽
$str=preg_replace("/javascript/si","Javascript",$str); //過濾script標簽
$str=preg_replace("/vbscript/si","Vbscript",$str); //過濾script標簽
$str=preg_replace("/on([a-z]+)\s*=/si","On\\1=",$str); //過濾script標簽
$str=preg_replace("/&#/si","&＃",$str); //過濾script標簽，如javAsCript:alert('aabb)*/
//清除空格和換行
$str = trim($str); //清除字符串兩邊的空格
$str = strip_tags($str,""); //利用php自帶的函數清除html格式
$str = preg_replace("/\t/","",$str); //使用正則表達式替換內容，如：空格，換行，並將替換為空。
$str = preg_replace("/\r\n/","",$str);
$str = preg_replace("/\r/","",$str);
$str = preg_replace("/\n/","",$str);
$str = preg_replace("/ /","",$str);
$str = preg_replace("/ /","",$str); //匹配html中的空格
$str = preg_replace("/(s*?r?ns*?)+/","n",$str); //去除字符串內部的空行：
$str = preg_replace('/($s*$)|(^s*^)/m', '',$str); //去除全部的空行，包括內部和頭尾
return trim($str);
}
轉自：http://www.shuchengxian.com/article/691.html