报错下标越界，怎么解决！！！

这是一段接受表单中文本框传过来的的值，并打印！但是报了下面的错，不知道怎么解决，求助。。。
                 keyword= request("keyword")
        If keyword <>"" then
           keyword=replace(keyword,"'"," ")
           keyword=replace(keyword,"，"," ")
           keyword=replace(keyword,"["," ")
           keyword=replace(keyword,"]"," ")
           keyword=replace(keyword,","," ")
           keyword=ltrim(rtrim(keyword))
           keywordlist=split(keyword," ")
           for  i=0 to ubound(keywordlist)
           keywordlist(i)=trim(keywordlist(i))
           
           next
           response.Write(keywordlist(i))
        end if
这段代码的错误提示：

Source line: response.Write(keywordlist(i))
Description: 下标越界: 'i'

可以帮我看看么！麻烦啦 !!!