ASP security detection and filtering function Safecheck

'--------------------------------------------------------------------------
' Role: Secure string detection function
' Name: Safecheck
' Parameter: checkstring,checktype,checklength
Description
' Checkstring to detect string: any character.
' Checktype detection type 0 normal short character 1 digit 2nd period 3 Money 4 encoded HTML5 decoding HTML6 login string 7 anti-attack detection
' Checklength detection type length: type int, position of decimal point when money is
' Return value: If the correct string is returned by detection,
' Return error code if not passed system_error| Error_code
' Script writen by:snowdu (Duche. NET)
' web:http://www.snsites.com/
'--------------------------------------------------------------------------
function Safecheck (checkstring,checktype,checklength)
On Error Resume Next
errorroot= "system_error|"
If checkstring= "" Then
safecheck=errorroot& "00001"
Exit function
End If
Checkstring=replace (checkstring, "'", "& #39")
Select Case Checktype
Case 0
Checkstring=trim (checkstring)
Safecheck=left (Checkstring,checklength)
Case 1
If not isnumberic (checkstring) Then
safecheck=errorroot& "00002"
Exit function
Else
Safecheck=left (Checkstring,checklength)
End If
Case 2
Tempvar=isdate (checkstring)
If not TempVar then
safecheck=errorroot& "00003"
Exit function
Else
Select Case Checklength
Case 0
Safecheck=formatdatetime (Checkstring,vbshortdate)
Case 1
Safecheck=formatdatetime (Checkstring,vblongdate)
Case 2
Safecheck=checkstring
End Select
End If
Case 3
Tempvar=formatcurrency (checkstring,0)
If Err Then
safecheck=errorroot& "00004"
Exit function
Else
Safecheck=formatcurrency (Checkstring,checklength)
End If
Case 4
Stemp = checkstring
If IsNull (stemp) = True Then
safecheck=errorroot& "00005"