asp function to recode dangerous characters for SQL injection

<%

'*********************************

'Function: CheckStr(byValChkStr)

'Parameter: ChkStr, character to be verified

'Author: Alixi

'Date: 2007/7/15

'Description: Reencode the SQL injection dangerous characters

'Example: CheckStr("and1=1orselect*from")

'*********************************

FunctionCheckStr(byValChkStr)

DimStr:Str=ChkStr

Str=Trim(Str)

IfIsNull(Str)Then

CheckStr=""

ExitFunction

EndIf

Dimre

Setre=newRegExp

re.IgnoreCase=True

re.Global=True

re.Pattern="(/r/n){3,}"

Str=re.Replace(Str,"$1$1$1")

Setre=Nothing

Str=Replace(Str,"'","''")

Str=Replace(Str,"select","select")

Str=Replace(Str,"join","join")

Str=Replace(Str,"union","union")

Str=Replace(Str,"where","where")

Str=Replace(Str,"insert","insert")

Str=Replace(Str,"delete","delete")

Str=Replace(Str,"update","update")

Str=Replace(Str,"like","like")

Str=Replace(Str,"drop","drop")

Str=Replace(Str,"create","create")

Str=Replace(Str,"modify","modify")

Str=Replace(Str,"rename","rename")

Str=Replace(Str,"alter","alter")

Str=Replace(Str,"cast","cast")

CheckStr=Str

EndFunction

'Decompile the string processed by the above function

FunctionUnCheckStr(Str)

Str=Replace(Str,"select","select")

Str=Replace(Str,"join","join")

Str=Replace(Str,"union","union")

Str=Replace(Str,"where","where")

Str=Replace(Str,"insert","insert")

Str=Replace(Str,"delete","delete")

Str=Replace(Str,"update","update")

Str=Replace(Str,"like","like")

Str=Replace(Str,"drop","drop")

Str=Replace(Str,"create","create")

Str=Replace(Str,"modify","modify")

Str=Replace(Str,"rename","rename")

Str=Replace(Str,"alter","alter")

Str=Replace(Str,"cast","cast")