辐射4 聚落防御:代码问题，急求高手帮忙，。。。。。。

请问，为什么我加入以下防SQL注入代码后，在表单中提交数据会被提示含有非法字符？到底怎么样的是非法字符？怎么才是合法的字符？
<%
Dim Fy_Post,Fy_Get,Fy_In,Fy_Inf,Fy_Xh,Fy_db,Fy_dbstr
'自定义需要过滤的字串,用 "枫" 分隔
Fy_In = "'枫;枫and枫exec枫insert枫select枫delete枫update枫count枫*枫%枫chr枫mid枫master枫truncate枫char枫declare"
'----------------------------------
%>

<%
Fy_Inf = split(Fy_In,"枫")
'--------POST部份------------------
If Request.Form<>"" Then
For Each Fy_Post In Request.Form

For Fy_Xh=0 To Ubound(Fy_Inf)
If Instr(LCase(Request.Form(Fy_Post)),Fy_Inf(Fy_Xh))<>0 Then
'--------写入数据库-------头--------
Fy_dbstr="DBQ="+server.mappath("SqlIn.mdb")+";DefaultDir=;DRIVER={Microsoft Access Driver (*.mdb)};"
Set Fy_db=Server.CreateObject("ADODB.CONNECTION")
Fy_db.open Fy_dbstr
Fy_db.Execute("insert into SqlIn(Sqlin_IP,SqlIn_Web,SqlIn_FS,SqlIn_CS,SqlIn_SJ) values('"&Request.ServerVariables("REMOTE_ADDR")&"','"&Request.ServerVariables("URL")&"','POST','"&Fy_Post&"','"&replace(Request.Form(Fy_Post),"'","''")&"')")
Fy_db.close
Set Fy_db = Nothing
'--------写入数据库-------尾--------

Response.Write "<Script Language=JavaScript>alert('系统提示↓\n\n请不要在参数中包含非法字符尝试注入！\n\n ');</Script>"
Response.Write "非法操作！系统做了如下记录↓<br>"
Response.Write "操作IP："&Request.ServerVariables("REMOTE_ADDR")&"<br>"
Response.Write "操作时间："&Now&"<br>"
Response.Write "操作页面："&Request.ServerVariables("URL")&"<br>"
Response.Write "提交方式：POST<br>"
Response.Write "提交参数："&Fy_Post&"<br>"
Response.Write "提交数据："&Request.Form(Fy_Post)
Response.End
End If
Next

Next
End If
'----------------------------------

'--------GET部份-------------------
If Request.QueryString<>"" Then
For Each Fy_Get In Request.QueryString

For Fy_Xh=0 To Ubound(Fy_Inf)
If Instr(LCase(Request.QueryString(Fy_Get)),Fy_Inf(Fy_Xh))<>0 Then
''--------写入数据库-------头--------
Fy_dbstr="DBQ="+server.mappath("SqlIn.mdb")+";DefaultDir=;DRIVER={Microsoft Access Driver (*.mdb)};"
Set Fy_db=Server.CreateObject("ADODB.CONNECTION")
Fy_db.open Fy_dbstr
Fy_db.Execute("insert into SqlIn(Sqlin_IP,SqlIn_Web,SqlIn_FS,SqlIn_CS,SqlIn_SJ) values('"&Request.ServerVariables("REMOTE_ADDR")&"','"&Request.ServerVariables("URL")&"','GET','"&Fy_Get&"','"&replace(Request.QueryString(Fy_Get),"'","''")&"')")
Fy_db.close
Set Fy_db = Nothing
Response.Write "<Script Language=JavaScript>alert('系统提示↓\n\n请不要在参数中包含非法字符尝试注入！\n\n');</Script>"
Response.Write "非法操作！系统做了如下记录↓<br>"
Response.Write "操作IP："&Request.ServerVariables("REMOTE_ADDR")&"<br>"
Response.Write "操作时间："&Now&"<br>"
Response.Write "操作页面："&Request.ServerVariables("URL")&"<br>"
Response.Write "提交方式：GET<br>"
Response.Write "提交参数："&Fy_Get&"<br>"
Response.Write "提交数据："&Request.QueryString(Fy_Get)
Response.End
End If
Next
Next
End If
%>