ASP practical function Library source code (i)

The following code is my recent collation of the common code part, and I will release more practical code, please put your own code back, while I tidy up, thank you!
qq:393356
<%
' Determine if the file name is legitimate
Function Isfilename (Afilename)
Dim Serrorstr,inamelength,i
Isfilename=true
Serrorstr=array ("/", "", ":", "*", "?", "" "", "<", ">", "|")
Inamelength=len (Afilename)
If inamelength<1 Or inamelength=null Then
Isfilename=false
Else
For I=0 to 8
If InStr (Afilename,serrorstr (i)) Then
Isfilename=false
End If
Next
End If
End Function
' Get rid of consecutive carriage returns and spaces at the ends of a string
function Trimvbcrlf (str)
TRIMVBCRLF=RTRIMVBCRLF (Ltrimvbcrlf (str))
End Function
' Remove successive carriage returns and spaces at the beginning of the string
function Ltrimvbcrlf (str)
Dim Pos,isblankchar
Pos=1
Isblankchar=true
While Isblankchar
If mid (str,pos,1) = "" Then
Pos=pos+1
ElseIf Mid (str,pos,2) =vbcrlf Then
Pos=pos+2
Else
Isblankchar=false
End If
Wend
Ltrimvbcrlf=right (Str,len (str)-pos+1)
End Function
' Remove consecutive carriage returns and spaces at the end of the string
function Rtrimvbcrlf (str)
Dim Pos,isblankchar
Pos=len (str)
Isblankchar=true
While Isblankchar and pos>=2
If mid (str,pos,1) = "" Then
Pos=pos-1
ElseIf Mid (str,pos-1,2) =vbcrlf Then
Pos=pos-2
Else
Isblankchar=false
End If
Wend
Rtrimvbcrlf=rtrim (Left (Str,pos))
End Function
' To determine if an email is valid, return 1 to indicate the correct
Function Isemail (Aemail)
Dim Ilocat,v,ilength,i,checkletter
If InStr (Aemail, "@") = 0 Or InStr (Aemail, ".") = 0 Then
Isemail=0
EXIT FUNCTION
End If
Ilocat=instr (Aemail, "@")
If InStr (Ilocat,aemail, ".") =0 Or InStr (Ilocat+1,aemail, "@") >0 Then