var dtCh= "-";
var minYear=1900;
var maxYear=2100;

function isInteger(s){
	var i;
    for(i = 0; i < s.length; i++)
    {
        // Check that current character is number.
        var c = s.charAt(i);
        if ((c < "0") || (c > "9")) return false;
    }
    // All characters are numbers.
    return true;
}

function stripCharsInBag(s, bag){
	var i;
    var returnString = "";
    // Search through string's characters one by one.
    // If character is not in bag, append to returnString.
    for (i = 0; i < s.length; i++){
        var c = s.charAt(i);
        if (bag.indexOf(c) == -1) returnString += c;
    }
    return returnString;
}

function daysInFebruary (year){
	// February has 29 days in any year evenly divisible by four,
    // EXCEPT for centurial years which are not also divisible by 400.
    return (((year % 4 == 0) && ( (!(year % 100 == 0)) || (year % 400 == 0))) ? 29 : 28 );
}
function DaysArray(n) {
	for (var i = 1; i <= n; i++) {
		this[i] = 31
		if (i==4 || i==6 || i==9 || i==11) {this[i] = 30}
		if (i==2) {this[i] = 29}
   }
   return this
}

function isDate(dtStr){
	var daysInMonth = DaysArray(12);
	var pos1=dtStr.indexOf(dtCh);
	var pos2=dtStr.indexOf(dtCh,pos1+1);

	var strDay=dtStr.substring(0,pos1);
	var strMonth=dtStr.substring(pos1+1,pos2);
	var strYear=dtStr.substring(pos2+1);

	strYr=strYear;
	if (strDay.charAt(0)=="0" && strDay.length>1) strDay=strDay.substring(1)
	if (strMonth.charAt(0)=="0" && strMonth.length>1) strMonth=strMonth.substring(1)
	for (var i = 1; i <= 3; i++) {
		if (strYr.charAt(0)=="0" && strYr.length>1) strYr=strYr.substring(1)
	}

	month=parseInt(strMonth);
	day=parseInt(strDay);
	year=parseInt(strYr);

	if (pos1==-1 || pos2==-1){
		alert("The date format should be : dd-mm-yyyy");
		return false;
	}

	if (strMonth.length<1 || month<1 || month>12){
		alert("Please enter a valid month");
		return false;
	}

	if (strDay.length<1 || day<1 || day>31 || (month==2 && day>daysInFebruary(year)) || day > daysInMonth[month]){
		alert("Please enter a valid day");
		return false;
	}
	if (strYear.length != 4 || year==0 || year<minYear || year>maxYear){
		alert("Please enter a valid 4 digit year between "+minYear+" and "+maxYear);
		return false
	}
	if (dtStr.indexOf(dtCh,pos2+1)!=-1 || isInteger(stripCharsInBag(dtStr, dtCh))==false){
		alert("Please enter a valid date");
		return false;
	}
return true
}

function emailCheck (emailStr) {

  /*
  This script and many more are available free online at
  The JavaScript Source!! http://javascript.internet.com

  V1.1.3: Sandeep V. Tamhankar (stamhankar@hotmail.com)
  Original:  Sandeep V. Tamhankar (stamhankar@hotmail.com)
  */

  var checkTLD=1;
  var knownDomsPat=/^(com|net|org|edu|int|mil|gov|arpa|biz|aero|name|coop|info|pro|museum)$/;
  var emailPat=/^(.+)@(.+)$/;
  var specialChars="\\(\\)><@,;:\\\\\\\"\\.\\[\\]";
  var validChars="\[^\\s" + specialChars + "\]";
  var quotedUser="(\"[^\"]*\")";
  var ipDomainPat=/^\[(\d{1,3})\.(\d{1,3})\.(\d{1,3})\.(\d{1,3})\]$/;

  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 +")*$");

  var matchArray=emailStr.match(emailPat);

  if (matchArray==null) {
    alert("The e-mail address seems incorrect. Please check @ and .'s and try again.");
    return false;
  }

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

  for (i=0; i<user.length; i++) {
    if (user.charCodeAt(i)>127) {
      alert("Ths username part of the e-mail address contains invalid characters.");
      return false;
    }
  }

  for (i=0; i<domain.length; i++) {
    if (domain.charCodeAt(i)>127) {
      alert("The domain name in the e-mail address contains invalid characters. Please try again.");
      return false;
    }
  }

  if (user.match(userPat)==null) {
    alert("The username in the given e-mail address doesn't seem to be valid. Please try again.");
    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("Sorry. The destination IP address in the given e-mail address is invalid. Please try again.");
        return false;
      }
    }

    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) {
      alert("Sorry. The domain name in your e-mail address does not seem to be valid. Please try again.");
      return false;
    }
  }

  /*
  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) {
    alert("The e-mail address must end in a well-known domain or two letter " + "country. Please try again.");
    return false;
  }

  // Make sure there's a host name preceding the domain.

  if (len<2) {
    alert("This e-mail address is missing a hostname. Please try again.");
    return false;
  }

  return true;
}