function isValidMailId (s)
{   
    if (isBlank(s)) return true;
    
    // is s whitespace?
    if (isWhitespace(s)) return true;
    
    // there must be >= 1 character before @, so we
    // start looking at character position 1 
    // (i.e. second character)
    var i = 1;
    var sLength = s.length;
 
  if(!s.match(/^[a-z0-9\#\=\-\.\/\_\@\+]+$/i))
  return true;
 
    // look for @
    while ((i < sLength) && (s.charAt(i) != "@"))
    { i++
    }
 
    if ((i >= sLength) || (s.charAt(i) != "@")) return true;
    else i += 2;
 
    // look for .
    while ((i < sLength) && (s.charAt(i) != "."))
    { i++
    }
 
    // there must be at least one character after the .
    if ((i >= sLength - 1) || (s.charAt(i) != ".")) return true;
    else return false;
}
 
 
function isBlank(s)
{   return ((s == null) || (s.length == 0))
}
 
 
function isWhitespace (s)
{   
 var i;
 var whitespace = " \t\n\r";
 
    // Is s empty?
    if (isBlank(s)) return true;
 
    // Search through string's characters one by one
    // until we find a non-whitespace character.
    // When we do, return false; if we don't, return true.
 
    for (i = 0; i < s.length; i++)
    {   
        // Check that current character isn't whitespace.
        var c = s.charAt(i);
 
        if (whitespace.indexOf(c) == -1) return false;
    }
 
    // All characters are whitespace.
    return true;
}