验证电子邮件地址
<%
'验证Str是否是合法的电子邮件地址
Public Function ValidEmail(Str)
    Dim StrArray, TempStr, I, TempChar
    ValidEmail = True
    StrArray = Split(Str, "@")
    If UBound(StrArray) <> 1 Then
 '如果不含有"@"或者含有多个"@"，未能通过验证
        ValidEmail = False
        Exit Function
    End If
    For Each TempStr in StrArray
        If Len(TempStr) <= 0 Then
       '如果数组中的元素为空字符串，未能通过验证
            ValidEmail = False
            Exit Function
        End If
        For I = 1 to Len(TempStr)
            TempChar = LCase(Mid(TempStr, I, 1))
            If InStr("abcdefghijklmnopqrstuvwxyz_-.", TempChar) <= 0 And Not IsNumeric(TempChar) Then
                '如果不是字母、数字以及"_"、"-"、"."等特殊字符，则为非法字符，未能通过验证
    ValidEmail = False
                Exit Function
            End If
        Next
        If Left(TempStr, 1) = "." Or Right(TempStr, 1) = "." Then
  '如果"."在字符串的最前或最后，未能通过验证
   ValidEmail = False
            Exit Function
        End If
    Next
    If InStr(StrArray(1), ".") <= 0 Then
        '如果@后没有"."，未能通过验证
  ValidEmail = False
        Exit Function
    End If
    I = Len(StrArray(1)) - InStrRev(StrArray(1), ".")
    If I <> 2 And I <> 3 Then
       '如果"."位置错误，未能通过验证
        ValidEmail = False
        Exit Function
    End If
    If InStr(Str, "..") > 0 Then
  '如果含有".."，未能通过验证
        ValidEmail = False
    End If
End Function
%>

--------------------------------

function ValidEmail(item)
{
var etext
var elen
var i
var aa
etext=item
elen=etext.length
if (elen<5)
 return true;
i= etext.indexOf("@",0)
if (i==0 || i==-1 || i==elen-1)
 return true;
else
 {if (etext.indexOf("@",i+1)!=-1)
  return true;}
if (etext.indexOf("..",i+1)!=-1)
 return true;
i=etext.indexOf(".",0)
if (i==0 || i==-1 || etext.charAt(elen-1)=='.')
 return true;
if ( etext.charAt(0)=='-' ||  etext.charAt(elen-1)=='-')
 return true;
if ( etext.charAt(0)=='_' ||  etext.charAt(elen-1)=='_')
 return true;
for (i=0;i<=elen-1;i++)
{ aa=etext.charAt(i)
  if (!((aa=='.') || (aa=='@') || (aa=='-') ||(aa=='_') || (aa>='0' && aa<='9') || (aa>='a' && aa<='z') || (aa>='A' &&

aa<='Z')))
   return true;
}
return false;
}

if (ValidEmail(form1.mail.value))
  {
  alert("请输入有效的Email地址!") ;
  form1.mail.focus();
  return false ;}

--------------------------------

<%
Function isemail(strng)
isemail = false
Dim regEx, Match
Set regEx = New RegExp
regEx.Pattern = "^/w+((-/w+)|(/./w+))*/@[A-Za-z0-9]+((/.|-)[A-Za-z0-9]+)*/.[A-Za-z0-9]+$"
regEx.IgnoreCase = True
Set Match = regEx.Execute(strng)
if match.count then isemail= true
End Function
%>

--------------------------------

function chkEmail(email)
on error resume next
dim i,l,pos1,pos2
chkEmail=true
if isnull(email) then chkEmail=false:exit function
pos1= instr(email,"@")
pos2=instrRev(email,".")
if not(pos1>0) or not (pos2>0) or pos1>pos2 then
chkEmail=false
end if
if err.number<>0 then err.clear
end function

--------------------------------

function chk_input(theform)
{
  var email = theform.Email.value;
　var pattern = /^([a-zA-Z0-9_-])+@([a-zA-Z0-9_-])+(/.[a-zA-Z0-9_-])+/;
　flag = pattern.test(email);
　if(!flag)
　{
　alert("email格式不正确!");
theform.Email.focus();
　return false;
　}

return (true);
}