JavaScript Verify Mailbox

Method One

var myreg =/^ ([a-za-z0-9]+[_|_|.]?) *[a-za-z0-9]+@ ([a-za-z0-9]+[_|_|.]?) *[a-za-z0-9]+. [A-za-z] {2,3}$/;
if (!myreg.test (Document.adddata.email.value))
{
Alert ("Email is wrong!");
Document.adddata.email.select ();
return false;
}

Method Two

E-mail verification culvert number

function Isemail (s)
{
 var i=1;
 var slength=s.length;
 while ((i<slength) && (S.charat (i)!= "@")
 {
  i++;
 }
 //does not exist @ return false
 if (i>=slength) | | (S.charat (i)!= "@"))
  return false;
 else
  i+=2;
 //find '. ' The location of
 while (i<slength) && (S.charat (i)!= "."))
 {
  i++;
 }
 //if not found. Definitely not a valid email
 if (i>=slength-1) | | (S.charat (i)!= "."))
  return false;
 else
  return true;
}