function trimString(sInString) {
  sInString = sInString.replace( /^\s+/g, "" );// strip leading
  return sInString.replace( /\s+$/g, "" );// strip trailing
}

function removeAllWhiteChars(sInString) {
  return sInString.replace( /\s+/g, "" );
}

function lTrimAllZeros(sInString) {
  return sInString.replace( /^0+/g, "" );// strip leading
}

function isStringEmpty(str)
{
    return str == null || str.length == 0;
}

function clearRegisterForm()
{
    var doc = document.forms[0];

    try {
        doc.ShipmentTextBox.value = "";
        doc.EmailTextBox.value = "";
        doc.MobileTextBox.value = "";
    } catch(e) {}
}

function isValidEmail(emailStr)
{
//    return !isStringEmpty(str);
    /* 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. */
    	//alert("Email address seems incorrect (check @ and .'s)")
	    return false
    }
    var user=matchArray[1]
    var domain=matchArray[2]

    // See if "user" is valid
    if (user.match(userPat)==null) {
        // user is not valid
        //alert("The part of your email address before the '@' doesn't seem to be valid.")
        return false
    }

    /* 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) {
    	        //alert("Destination IP address is invalid!")
    		return false
    	    }
        }
        return true
    }

    // Domain is symbolic name
    var domainArray=domain.match(domainPat)
    if (domainArray==null) {
	    //alert("Part of your email address after the '@' doesn't seem to be valid")
        return false
    }

    /* domain name seems valid, but now make sure that it ends in a
       three-letter word (like com, edu, gov) or a two-letter word,
       representing country (uk, nl), and that there's a hostname preceding
       the domain or country. */

    /* Now we need to break up the domain to get a count of how many atoms
       it consists of. */
    var atomPat=new RegExp(atom,"g")
    var domArr=domain.match(atomPat)
    var len=domArr.length
    if (domArr[domArr.length-1].length<2 ||
        domArr[domArr.length-1].length>6) {
       // the address must end in a two letter or other TLD including museum
       //alert("The address must end in a top level domain (e.g. .com), or two letter country.")
       return false
    }

    // Make sure there's a host name preceding the domain.
    if (len<2) {
       var errStr="This address is missing a hostname!"
       //alert(errStr)
       return false
    }

    // If we've got this far, everything's valid!
    return true
}

function isValidMobile(str)
{
    if (str == null || str.length != 9)
        return false;

    for (i = 0; i < str.length; i++) {
        var c = str.charAt(i);
        if (c < "0" || c > "9")
            return false;
    }

    return true;
}

function isEmailVisible()
{
    try {
        var val = document.forms[0].EmailTextBox.value;
        return true;
    } catch(e) {
        return false;
    }
}

function isMobileVisible()
{
    try {
        var val = document.forms[0].MobileTextBox.value;
        return true;
    } catch(e) {
        return false;
    }
}

function getEmail()
{
    try {
        var val = document.forms[0].EmailTextBox.value;
        return trimString(val);
    } catch(e) {
        return null;
    }
}

function getMobile()
{
    try {
        var val = document.forms[0].MobileTextBox.value;
        return lTrimAllZeros(removeAllWhiteChars(val));
    } catch(e) {
        return null;
    }
}

function getShipment()
{
    var val = document.forms[0].ShipmentTextBox.value;
    return trimString(val);
}

function confirmSubmit()
{
    var shipment = getShipment();
    var mobile = getMobile();
    var email = getEmail();

    if (isStringEmpty(shipment))
    {
        alert("wpisz numer przesyłki");
        return false;
    }

    if (isMobileVisible() && isEmailVisible())
    {
        if (!isValidEmail(email) && !isValidMobile(mobile))
        {
            alert("wpisz poprawny e-mail i/lub telefon komórkowy");
            return false;
        }
    }
    else if (isMobileVisible())
    {
        if (!isValidMobile(mobile))
        {
            alert("wpisz poprawny telefon komórkowy");
            return false;
        }
    }
    else if (isEmailVisible())
    {
        if (!isValidEmail(email))
        {
            alert("wpisz poprawny adres e-mail");
            return false;
        }
    }

    return true;
}