// Common functions used by all webpages

// Group of related functions that support "isDate" function ///////////////////////////////////////////////////////
// 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 strDay=dtStr.substring(0,pos1);
	var strMonth=dtStr.substring(pos1+1,pos2);
	var strYear=dtStr.substring(pos2+1);
	strYr=strYear;
	if (dtStr == "") return true;
	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){
	if (strYear.length != 4 || year==0 || year<minYear || year>maxYear){
		alert(strYear.length);
		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 isNumeric(input)
{ 
  	var characters = "0123456789."; 
  	var response = true; 
  	for(i=0; (i<input.length && response); i++)
    { 
    	if(characters.indexOf(input.charAt(i)) == -1) // Not a number
    		response = false; 
    } 
    return response; 
}

function trim(string) // remove leading and trailing spaces
{
   //Remove leading spaces
   while(string.charAt(0) == ' ')
      string = string.substring(1, string.length);

   //Remove trailing spaces
   while(string.charAt(string.length-1) == ' ')
      string = string.substring(string, string.length-1);

   return string;
}

function GetString()
{
	var i;
	var sReqStr = "";
	
	for (i = 0; i < document.form1.length; i++){
		sReqStr = sReqStr + document.form1[i].name + "=" + trim(document.form1[i].value) + "&" ;		
	}
	return sReqStr;
}

function checkDate(sControl)  // check for Date input
{
	if (isDate(trim(document.form1[sControl].value)) == true)
		document.form1[sControl].style.backgroundColor = "white";
	else{
		//alert(sControl + " must be a Date");	
		document.form1[sControl].style.backgroundColor = "yellow";    //"#FFFFC6";		
		document.form1[sControl].focus();
		document.form1[sControl].select();
	}
}

function CheckNumber(sControl)			//check for number only 
{
	if (isNumeric(trim(document.form1[sControl].value)) == true)
		document.form1[sControl].style.backgroundColor = "white";
	else{
		alert(sControl + " must be a number");	
		document.form1[sControl].style.backgroundColor = "yellow";    //"#FFFFC6";		
		document.form1[sControl].focus();
		document.form1[sControl].select();
	}
}

function checkTime(sControl)  // check for valid TIME
{
	if (IsValidTime(trim(document.form1[sControl].value)) == true)
		document.form1[sControl].style.backgroundColor = "white";
	else{
		//alert(sControl + " must be a TIME");	
		document.form1[sControl].style.backgroundColor = "yellow";    //"#FFFFC6";		
		document.form1[sControl].focus();
		document.form1[sControl].select();
	}
}

function IsValidTime(timeStr) {
// Checks if time is in HH:MM:SS AM/PM format.
// The seconds and AM/PM are optional.

	var timePat = /^(\d{1,2}):(\d{2})(:(\d{2}))?(\s?(AM|am|PM|pm))?$/;

	var matchArray = timeStr.match(timePat);
	if (matchArray == null) {
		alert("Time is not in a valid format.");
		return false;
	}
	hour = matchArray[1];
	minute = matchArray[2];
	second = matchArray[4];
	ampm = matchArray[6];

	if (second=="") { second = null; }
	if (ampm=="") { ampm = null }

	if (hour < 0  || hour > 23) {
		alert("Hour must be between 1 and 12. (or 0 and 23 for military time)");
		return false;
	}
	if (hour <= 12 && ampm == null) {
		if (confirm("Please indicate which time format you are using.  OK = Standard Time, CANCEL = Military Time")) {
		alert("You must specify AM or PM.");
		return false;
   		}
	}
	if  (hour > 12 && ampm != null) {
		alert("You can't specify AM or PM for military time.");
		return false;
	}
	if (minute<0 || minute > 59) {
		alert ("Minute must be between 0 and 59.");
		return false;
	}
	if (second != null && (second < 0 || second > 59)) {
		alert ("Second must be between 0 and 59.");
		return false;
	}
	return true;
}

function ShowHelp(Action)
{
	var myMsg;
	myMsg = "Group A = standard static site, virtual hosting enviroment, no email.\n";
	myMsg = myMsg + "Group AA = standard static site with a cgi-bin, virtual hosting enviroment, no email.\n";
	myMsg = myMsg + "Group AAA = standard static site with a php, virtual hosting enviroment, no email.\n";
	myMsg = myMsg + "Group B = standard static site, non standard virtual hosting enviroment, no email.\n";
	myMsg = myMsg + "Group C = non standard site, non standard virtual hosting enviroment, no email.";
	alert (myMsg);	   
}