$query = mysql_query("
 UPDATE users SET
 Name = '".mysql_real_escape_string($name)."',
 City = '".mysql_real_escape_string($city)."',
 Address = '".mysql_real_escape_string($address)."',
 Email = '".mysql_real_escape_string($email)."',
 Mobile = '".mysql_real_escape_string($mobile)."'
 WHERE Username = '$username'
 ") or die(mysql_error());