function emailCheck (emailStr)
{
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=/^\[(\d{1,3})\.(\d{1,3})\.(\d{1,3})\.(\d{1,3})\]$/;
var atom=validChars + '+';
var word="(" + atom + "|" + quotedUser + ")";
var userPat=new RegExp("^" + word + "(\\." + word + ")*$");
var domainPat=new RegExp("^" + atom + "(\\." + atom +")*$");
var matchArray=emailStr.match(emailPat);

if (matchArray==null) {
	alert("Email address seems incorrect (check @ and .'s)");
	return false;
}
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)
	{
		alert("Ths username contains invalid characters.");
		return false;
	}
}
for (i=0; i<domain.length; i++)
{
	if (domain.charCodeAt(i)>127)
	{
		alert("Ths domain name contains invalid characters.");
		return false;
	}
}

// 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.  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("The domain name does not seem to be valid.");
		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 address must end in a well-known domain or two letter " + "country.");
	return false;
}

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

if (len<2)
{
	alert("This address is missing a hostname!");
	return false;
}

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

function FdateCheck(strDate)
{
	var fSlash,sSlash;
	var strDay,strMonth,strYear;
	var iDay,iMonth,iYear;

	fSlash = strDate.indexOf('/',0);
	sSlash = strDate.indexOf('/',fSlash+1);
	strDay = strDate.substring(0,fSlash);
	strMonth = strDate.substring(fSlash+1,sSlash);
	strYear = strDate.substring(sSlash+1);
	iDay = parseInt(strDay);
	iMonth = parseInt(strMonth);
	iYear = parseInt(strYear);

	if (isNaN(iDay) || isNaN(iMonth) || isNaN(iYear)) return false;
	if (iYear<0) return false;
	if ((iMonth<1)||(iMonth>12)) return false;
	if ((iMonth==1) || (iMonth==3) || (iMonth==5)||(iMonth==7) || (iMonth==8)|| (iMonth==10)|| (iMonth==12))
	{
		if ((iDay<0)||(iDay>31)) return false;
	}
	else if (iMonth==2)
	{
		if (iYear % 4 == 0){if ((iDay<0)||(iDay>29)) return false;}
		else if ((iDay<0)||(iDay>28)) return false;
	}
	else
	{
		if ((iDay<0)||(iDay>31)) return false;
	}
	return true;
}
function EdateCheck(strDate)
{
	var fSlash,sSlash;
	var strDay,strMonth,strYear;
	var iDay,iMonth,iYear;

	fSlash = strDate.indexOf('/',0);
	sSlash = strDate.indexOf('/',fSlash+1);
	strMonth = strDate.substring(0,fSlash);
	strDay = strDate.substring(fSlash+1,sSlash);
	strYear = strDate.substring(sSlash+1);
	iDay = parseInt(strDay);
	iMonth = parseInt(strMonth);
	iYear = parseInt(strYear);

	if (isNaN(iDay) || isNaN(iMonth) || isNaN(iYear)) return false;
	if (iYear<0) return false;
	if ((iMonth<1)||(iMonth>12)) return false;
	if ((iMonth==1) || (iMonth==3) || (iMonth==5)||(iMonth==7) || (iMonth==8)|| (iMonth==10)|| (iMonth==12))
	{
		if ((iDay<0)||(iDay>31)) return false;
	}
	else if (iMonth==2)
	{
		if (iYear % 4 == 0){if ((iDay<0)||(iDay>29)) return false;}
		else if ((iDay<0)||(iDay>28)) return false;
	}
	else
	{
		if ((iDay<0)||(iDay>30)) return false;
	}
	return true;
}

function isInt(so)
{
	var str="0123456789"
	for (var j=0;j<so.length;j++)
	  if (str.indexOf(so.charAt(j))==-1)
	  	return false;
	return true;
}
function isInts(so)
{
	var str="0123456789."
	for (var j=0;j<so.length;j++)
	  if (str.indexOf(so.charAt(j))==-1)
	  	return false;
	return true;
}

function isDomain(domain){
	var dom=/^(www.)\w?(\.)?(com|net|vn|org|edu|gov|arpa|biz|tk)$/i;
	var giaothuc="http://"+dom;
	var isValid=giaothuc.match(domain);
	return isValid;
}
function doUpload() {
	if (document.form1.fName.value.length==0) {
		alert("Please enter path and file name");
		document.form1.fName.focus();
		return false;
	}

	var filename = document.form1.fName.value;	
	var dotpos;
	filename = filename.substring(filename.lastIndexOf("\\")+1,filename.length);
	dotpos=filename.lastIndexOf('.');
	ext=filename.substr(dotpos+1,3);
	ext=ext.toLowerCase();
	if (ext!="")
		if ((ext!="gif") && (ext!="jpg") && (ext!="png")){
			alert("We only accept file format of GIF, JPG, PNG. Please try again.");
			return false;
		}
	document.form1.submit();
	return true;
}