function trim(str)
{
  var start = 0;
  var end = str.length;

  for(i = 0; i < str.length; i++)
  {
    if(str.charAt(i) == " ")
      start++;
    else
      break;
  }
  for(i = str.length-1; i >= 0; i--)
  {
    if(str.charAt(i) == " ")
      end--;
    else
      break;
  }

  if(end == 0)
    start = 0;
  str = str.substring(start,end);

  return str;
}

function valEmail(emailStr)
{
  /* The following variable tells the rest of the function whether or not
  to verify that the address ends in a two-letter country or well-known
  TLD.  1 means check it, 0 means don't. */
  var checkTLD=1;

  /* The following is the list of known TLDs that an e-mail address must end with. */
  var knownDomsPat=/^(com|net|org|edu|int|mil|gov|arpa|biz|aero|name|coop|info|pro|museum)$/;

  /* The following pattern is used to check if the entered e-mail address
  fits the user@domain format.  It also is used to separate the username
  from the domain. */
  var emailPat=/^(.+)@(.+)$/;

  /* The following string represents the pattern for matching all special
  characters.  We don't want to allow special characters in the address.
  These characters include ( ) < > @ , ; : \ " . [ ] */
  var specialChars="\\(\\)><@,;:\\\\\\\"\\.\\[\\]";

  /* The following string represents the range of characters allowed in a
  username or domainname.  It really states which chars aren't allowed.*/
  var validChars="\[^\\s" + specialChars + "\]";

  /* The following pattern applies if the "user" is a quoted string (in
  which case, there are no rules about which characters are allowed
  and which aren't; anything goes).  E.g. "jiminy cricket"@disney.com
  is a legal e-mail address. */
  var quotedUser="(\"[^\"]*\")";

  /* The following pattern applies for domains that are IP addresses,
  rather than symbolic names.  E.g. joe@[123.124.233.4] is a legal
  e-mail address. NOTE: The square brackets are required. */
  var ipDomainPat=/^\[(\d{1,3})\.(\d{1,3})\.(\d{1,3})\.(\d{1,3})\]$/;

  /* The following string represents an atom (basically a series of non-special characters.) */
  var atom=validChars + '+';

  /* The following string represents one word in the typical username.
  For example, in john.doe@somewhere.com, john and doe are words.
  Basically, a word is either an atom or quoted string. */
  var word="(" + atom + "|" + quotedUser + ")";

  // The following pattern describes the structure of the user
  var userPat=new RegExp("^" + word + "(\\." + word + ")*$");

  /* The following pattern describes the structure of a normal symbolic
  domain, as opposed to ipDomainPat, shown above. */
  var domainPat=new RegExp("^" + atom + "(\\." + atom +")*$");


  /* Finally, let's start trying to figure out if the supplied address is valid. */


  /* Begin with the coarse pattern to simply break up user@domain into
  different pieces that are easy to analyze. */
  var matchArray=emailStr.match(emailPat);
  if (matchArray == null)
  {
    /* Too many/few @'s or something; basically, this address doesn't
    even fit the general mould of a valid e-mail address. */
    error = "Napačen E-mail (preveri @ in pike)";
    return error;
  }

  var user=matchArray[1];
  var domain=matchArray[2];

  // Start by checking that only basic ASCII characters are in the strings (0-127).
  for (i=0; i < user.length; i++)
  {
    if (user.charCodeAt(i) > 127)
    {
      error = "Napačen E-mail (preveri del pred @)";
      return error;
    }
  }
  for (i=0; i < domain.length; i++)
  {
    if (domain.charCodeAt(i)>127)
    {
      error = "Napačen E-mail (preveri del za @)";
      return error;
    }
  }

  // See if "user" is valid
  if (user.match(userPat)==null)
  {
    // user is not valid
    error = "Napačen E-mail (preveri del pred @)";
    return error;
  }

  /* if the e-mail address is at an IP address (as opposed to a symbolic
  host name) make sure the IP address is valid. */
  var IPArray=domain.match(ipDomainPat);
  if (IPArray != null)
  {
    // this is an IP address
    for (var i=1;i <= 4;i++)
    {
      if (IPArray[i]>255)
      {
        error = "Napačen E-mail (ciljni IP je nepravilen)";
        return error;
      }
    }
    return true;
  }

  // Domain is symbolic name.  Check if it's valid.
  var atomPat=new RegExp("^" + atom + "$");
  var domArr=domain.split(".");
  var len=domArr.length;
  for (i=0;i<len;i++)
  {
    if (domArr[i].search(atomPat)==-1)
    {
      error = "Napačen E-mail (preveri del za @)";
      return error;
    }
  }

  /* domain name seems valid, but now make sure that it ends in a
  known top-level domain (like com, edu, gov) or a two-letter word,
  representing country (uk, nl), and that there's a hostname preceding
  the domain or country. */
  if (checkTLD && (domArr[domArr.length-1].length != 2) && (domArr[domArr.length-1].search(knownDomsPat) == -1))
  {
    error = "Napačen E-mail (preveri končnico)";
    return error;
  }

  // Make sure there's a host name preceding the domain.
  if (len < 2)
  {
    error = "Napačen E-mail (preveri del za @)";
    return error;
  }

  // If we've gotten this far, everything's valid!
  return "OK";
}

function check_reg(form)
{
  var empty = false;

  for(var i = 0; i < form.elements.length; i++)
  {
    form.elements[i].value = trim(form.elements[i].value);
    if(form.elements[i].value == "")
    {
      empty = true;
    }
    
  }
  
  if(empty == false)
  {
    if(form.Pass.value.length < 4)
    {
      alert("Geslo mora vsebovati najmanj 4 znake!");
      return false;  
    }
    
    if(form.Pass_new.value != form.Pass_check.value)
    {
      alert("Vtipkani gesli nista enaki!");
      return false;  
    }

    if(form.Pass.value == form.Nickname.value)
    {
      alert("Geslo ne sme biti enako kot nickname!");
      return false;  
    }
    
    if(form.Pogoji.checked != true)
    {
      alert("Strinjati se moraš s pogoji uporabe!");
      return false;  
    }

    email = valEmail(form.Email.value);

    if(email != "OK")
    {
      alert(email);
      return false;
    }
  }
  else
  {
    alert("Izpolni vsa polja!");
    return false;
  }
}

function check_blog(form)
{
  var empty = false;

  for(var i = 0; i < form.elements.length; i++)
  {
    form.elements[i].value = trim(form.elements[i].value);
    if(form.elements[i].value == "")
    {
      empty = true;
    }
    
  }
  
  if(empty == false)
  {    
    if(form.blogChk.checked != true)
    {
      alert("Odkljukaj da res želiš svoj blog!");
      return false;  
    }

    email = valEmail(form.Email.value);

    if(email != "OK")
    {
      alert(email);
      return false;
    }
  }
  else
  {
    alert("Izpolni vsa polja!");
    return false;
  }
}

function check_topic(form)
{
  var empty = false;

  for(var i = 0; i < form.elements.length; i++)
  {
    form.elements[i].value = trim(form.elements[i].value);
    if(form.elements[i].value == "")
    {
      if(form.elements[i].name != "Links[]")
        empty = true;
    }
    
  }
  
  if(empty == false)
  {    
    if(form.Category_id.options[form.Category_id.options.selectedIndex].value == "")
    {
      alert("Izberi kategorijo!");
      return false;  
    }
  }
  else
  {
    alert("Izpolni vsa polja!");
    return false;
  }
}

function check_art(form)
{
  var empty = false;

  for(var i = 0; i < form.elements.length; i++)
  {
    form.elements[i].value = trim(form.elements[i].value);
    if(form.elements[i].value == "")
    {
      empty = true;
    }
    
  }
  
  if(empty == false)
  {    
       return true;  
  }
  else
  {
    alert("Napiši pa le nekaj!");
    return false;
  }
}