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
}

function alphanumeric(alphane) {
	var numaric = alphane;
	for(var j=0; j<numaric.length; j++) {
		var alphaa = numaric.charAt(j);
		var hh = alphaa.charCodeAt(0);
		if((hh > 47 && hh<59) || (hh > 64 && hh<91) || (hh > 96 && hh<123)) {
		}
		else {
			return false;
		}
	}
	return true;
}

function trim(str) {
	while((''+str.charAt(0)==' ') || (''+str.charAt(0)=='\n') || (''+str.charAt(0)=='\r'))
		str=str.substring(1, str.length);
	while((''+str.charAt(str.length-1)==' ') || (''+str.charAt(str.length-1)=='\n') || (''+str.charAt(str.length-1)=='\r'))
		str=str.substring(0, str.length-1);
	return str;
}

function echeck(str) {
	var at="@"
	var dot="."
	var lat=str.indexOf(at)
	var lstr=str.length
	var ldot=str.indexOf(dot)

	if (str.indexOf(at)==-1){
	   alert("Invalid E-mail")
	   return false
	}

	if (str.indexOf(at)==-1 || str.indexOf(at)==0 || str.indexOf(at)==lstr){
	   alert("Invalid E-mail")
	   return false
	}

	if (str.indexOf(dot)==-1 || str.indexOf(dot)==0 || str.indexOf(dot)==lstr){
	    alert("Invalid E-mail")
	    return false
	}

	 if (str.indexOf(at,(lat+1))!=-1){
	    alert("Invalid E-mail")
	    return false
	 }

	 if (str.substring(lat-1,lat)==dot || str.substring(lat+1,lat+2)==dot){
	    alert("Invalid E-mail")
	    return false
	 }

	 if (str.indexOf(dot,(lat+2))==-1){
	    alert("Invalid E-mail")
	    return false
	 }

	 if (str.indexOf(" ")!=-1){
	    alert("Invalid E-mail")
	    return false
	 }

	 return true
}