/**
 * DHTML date validation script. Courtesy of SmartWebby.com (http://www.smartwebby.com/dhtml/)
 */
// Declaring valid date character, minimum year and maximum year
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 strMonth=dtStr.substring(0,pos1)
	var strDay=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 : mm/dd/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
}


<!-- EMAIL VALIDATION Changes:  Sandeep V. Tamhankar (stamhankar@hotmail.com) -->

/* 1.1.2: Fixed a bug where trailing . in e-mail address was passing
            (the bug is actually in the weak regexp engine of the browser; I
            simplified the regexps to make it work).
   1.1.1: Removed restriction that countries must be preceded by a domain,
            so abc@host.uk is now legal.  However, there's still the 
            restriction that an address must end in a two or three letter
            word.
     1.1: Rewrote most of the function to conform more closely to RFC 822.
     1.0: Original  */

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

<!-- Begin
function checkmiscemail (emailStr) {
/* 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 (emailStr != '') {
	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 username 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("The domain name 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>3) {
	   // the address must end in a two letter or three letter word.
	   alert("The address must end in a three-letter domain, 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 gotten this far, everything's valid!
	return true;
	}
}







function checkmiscdate(elem) {
var dt=elem;

if (dt.value != '') {
	if (isDate(dt.value)==false){
		dt.focus()
		return false
	}
}
}

function checkmiscdollar(elem) {
	var dollaramt = elem;
	
	if (dollaramt.value != '') {
		if (!(dollaramt.value.match(/^-?\d+(\.\d+)?$/))) {
			alert("You must provide a valid dollar amount for the price you are adding.");
			dollaramt.focus();
			return false;
		}
	}
}

function checkmiscdecimal(elem) {
	var decimalamt = elem;
	
	if (decimalamt.value != '') {
		if (!(decimalamt.value.match(/^-?\d+(\.\d+)?$/))) {
			alert("You must provide a valid decimal amount for the price you are adding.");
			decimalamt.focus();
			return false;
		}
	}
}

function checkmiscinteger(elem) {
	var num = elem;
	
	if (num.value != '') {
		if (!(num.value.match(/^-?\d+$/))) {
			alert("You must provide a valid integer for this amount.");
			num.focus();
			return false;
		}
	}
	
}

function checkmiscpositiveinteger(elem) {
	var num = elem;
	
	if (num.value != '') {
		if ((!(num.value.match(/^-?\d+$/)))) {
			alert("You must provide a valid integer for this amount.");
			num.focus();
			return false;
		}
		else if (num.value <= 0) {
			alert("You must provide a positive integer greater than zero for this amount .");
			num.focus();
			return false;
		}
	}
	
}

function checklength(elem, len) {
	
	if (elem.value.length > len) {
		alert("You have entered too many characters.  Please do not enter more than " + len + " characters.");
		elem.focus();
		return false;
	}
}