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 checkForm()
{
    var fname,lname,country,request,fname2,lname2;
      
    fname    = document.frmCart.txt_fname;
    lname    = document.frmCart.txt_lname;
	tel_no   = document.frmCart.txt_tel;
    fname2    = document.frmCart.txt_fname2;
    lname2    = document.frmCart.txt_lname2;
    country    = document.frmCart.sel_country;
    request	 = document.frmCart.txt_request;
	dt=document.frmCart.txt_arrival;
	dt2=document.frmCart.txt_arrival2;
   	   	
    
   	if(trim(fname.value) == '')
	    {
	        alert('Please enter your first name');
	        fname.focus();
	        return false;
	    }
	else if(trim(lname.value) == '')
	    {
	        alert('Please enter your last name');
	        lname.focus();
	        return false;
	    }
	 else if(trim(tel_no.value) == '')
	    {
	        alert('Please enter your Telephone Number');
	        lname.focus();
	        return false;
	    }
	 else if(trim(fname2.value) == '')
	    {
	        alert('Please enter gift recipient first name');
	        fname2.focus();
	        return false;
	    }
	else if(trim(lname2.value) == '')
	    {
	        alert('Please enter gift recipient last name');
	        lname2.focus();
	        return false;
	    }
	else if(trim(country.value) == 'none')
	    {
	        alert('Please enter your country');
	        country.focus();
	        return false;
	    }
	else if(!request[0].checked && !request[1].checked){
		alert('Please select when you want gift to be delivered')
   		return false;
	}
	else if (request[0].checked && isDate(dt.value)==false){
		dt.focus();
		return false;
	}
	
	else if (request[1].checked && isDate(dt2.value)==false){
		dt2.focus();
		return false;
	}
    
      
    else
    {
        var answer=confirm('Are you sure you want to proceed?');
        if (!answer){
        	return false;}
        	else
        	{
    	fname.value = trim(fname.value);
        lname.value = trim(lname.value);
        fname2.value = trim(fname2.value);
        lname2.value = trim(lname2.value);
        country.value = trim(country.value);
        return true;}
    }
    
    
}

/*
Strip whitespace from the beginning and end of a string
Input : a string
*/
function trim(str)
{
    return str.replace(/^\s+|\s+$/g,'');
}

/*
Check if a string is in valid email format. 
Returns true if valid, false otherwise.
*/
function isEmail(str)
{
    var regex = /^[-_.a-z0-9]+@(([-_a-z0-9]+\.)+(ad|ae|aero|af|ag|ai|al|am|an|ao|aq|ar|arpa|as|at|au|aw|az|ba|bb|bd|be|bf|bg|bh|bi|biz|bj|bm|bn|bo|br|bs|bt|bv|bw|by|bz|ca|cc|cd|cf|cg|ch|ci|ck|cl|cm|cn|co|com|coop|cr|cs|cu|cv|cx|cy|cz|de|dj|dk|dm|do|dz|ec|edu|ee|eg|eh|er|es|et|eu|fi|fj|fk|fm|fo|fr|ga|gb|gd|ge|gf|gh|gi|gl|gm|gn|gov|gp|gq|gr|gs|gt|gu|gw|gy|hk|hm|hn|hr|ht|hu|id|ie|il|in|info|int|io|iq|ir|is|it|jm|jo|jp|ke|kg|kh|ki|km|kn|kp|kr|kw|ky|kz|la|lb|lc|li|lk|lr|ls|lt|lu|lv|ly|ma|mc|md|mg|mh|mil|mk|ml|mm|mn|mo|mp|mq|mr|ms|mt|mu|museum|mv|mw|mx|my|mz|na|name|nc|ne|net|nf|ng|ni|nl|no|np|nr|nt|nu|nz|om|org|pa|pe|pf|pg|ph|pk|pl|pm|pn|pr|pro|ps|pt|pw|py|qa|re|ro|ru|rw|sa|sb|sc|sd|se|sg|sh|si|sj|sk|sl|sm|sn|so|sr|st|su|sv|sy|sz|tc|td|tf|tg|th|tj|tk|tm|tn|to|tp|tr|tt|tv|tw|tz|ua|ug|uk|um|us|uy|uz|va|vc|ve|vg|vi|vn|vu|wf|ws|ye|yt|yu|za|zm|zw)|(([0-9][0-9]?|[0-1][0-9][0-9]|[2][0-4][0-9]|[2][5][0-5])\.){3}([0-9][0-9]?|[0-1][0-9][0-9]|[2][0-4][0-9]|[2][5][0-5]))$/i;
    return regex.test(str);
}

function confirmReset(){
	var answer=confirm('Are you sure that you want to reset the form?');
	if(!answer){
		return false;}
		else{
			return true;}
}


function IsNumeric(sText)


{
   var ValidChars = "0123456789.";
   var IsNumber=true;
   var Char;

 
   for (i = 0; i < sText.length && IsNumber == true; i++) 
      { 
      Char = sText.charAt(i); 
      if (ValidChars.indexOf(Char) == -1) 
         {
         IsNumber = false;
         }
      }
   return IsNumber;
 
 }