Regular expression replace does not seem to work

Regular expression replace does not seem to work

Dim i As String = StripTags(Request.QueryString("i").ToString())
Response.Write(Request.QueryString("i"))
Response.Write(i)
then my function looks like:
Function StripTags(ByVal html As String) As String
' Remove HTML tags.
Response.Write(html)
Return Regex.Replace(html, "<.*?%>", String.Empty)
End Function
the query string is: &i='%3bWAIT>FOR%20DELAY%20'0%3a0%3a25'--
the output i'm getting is:
';WAIT>FOR DELAY '0:0:25'--';WAIT>FOR DELAY '0:0:25'--';WAIT>FOR DELAY
'0:0:25'--
doesn't look like it's working. what am i missing?? i'm tried from staring
at it for an hour!