how can we validate the email id

CREATE PROCEDURE [dbo].[InsertName_sp]
(
  @Email varchar(50)
)
AS
IF EXISTS(SELECT 'True' FROM Resource WHERE Email= @Email)
BEGIN

  SELECT 'This Email already exists!'
END
ELSE
BEGIN

  SELECT 'Email Added'
  INSERT into Resource(Email) VALUES(@Email)
END

INSERT INTO SomeTable (SomeText)
SELECT email
FROM (SELECT @email email) A
LEFT OUTER JOIN SomeTable B
ON A.email=B.SomeText
WHERE B.SomeText IS NULL

private bool IsValidEmail(string sEmailid)
{
    Regex EmailExpression = new Regex(@"\w+([-+.']\w+)*@\w+([-.]\w+)*\.\w+([-.]\w+)*");
    if(!EmailExpression.IsMatch(sEmailid))
        return false;
    else
        return true;
}

function validateEmail(email) {
    var re = /^(([^<>()[\]\\.,;:\s@\"]+(\.[^<>()[\]\\.,;:\s@\"]+)*)|(\
".+\"))@((\[[0-9]{1,3}\.[0-9]{1,3}\.[0-9]{1,3}\.[0-9]{1,3}\])|(([a-zA
-Z\-0-9]+\.)+[a-zA-Z]{2,}))$/;
    return re.test(email);
}

function ValidateEmail(mail)
{
 if (/^\w+([\.-]?\w+)*@\w+([\.-]?\w+)*(\.\w{2,3})+$/.test(myForm.emailAddr.value))
  {
    return (true)
  }
    alert("You have entered an invalid email address!")
    return (false)
}