过滤特殊字符

function stringFilter(arg){
 // Modify by CaoLiangGang20091020 Start
 var str = arg;
 
 // 如果存在转义字符，先将转义字符转换回来，防止在下面转义出错
 str = str.replace(/%23/g, "#");
 //str = str.replace(/%26/g, "&");
 str = str.replace(/%2B/g, "+");
 str = str.replace(/%25/g, "%");
 
 // 必须最先转换“%”，否则会对之前replace出来的“%”再次进行转换
 str = str.replace(/%/g, "%25");
 str = str.replace(/#/g, "%23")
 //str = str.replace(/&/g, "%26");
 str = str.replace(//+/g, "%2B");
 
 return str;
 // Modify by CaoLiangGang 20091020 End
}