// email
function checkEmail (formField, fielddesc, required) {
var error="";
if (required && formField.length == 0) {
   error = "An " + fielddesc + " is required.\n";
} else {
	if (formField.length != 0) {
        var emailFilter=/^.+@.+\..{2,3}$/;
        if (!(emailFilter.test(formField))) { 
           error = "Please enter a valid " + fielddesc + ".\n";
        } else {
          //test email for illegal characters
           var illegalChars= /[\(\)\<\>\,\;\:\\\"\[\]]/
           if (formField.match(illegalChars)) {
             error = "The " + fielddesc + " contains illegal characters.\n";
           }
        }
    }
}
return error;    
}


// (generic) number - strip out delimiters and check for digits only
function checkNum (formField, fielddesc, required, numtype) {

// numtype can be one of the following:
// 1 - 0123456789 -() (phone numbers)
// 2 - 0123456789     (whole numbers)
// 3 - 0123456789     (whole numbers and minuses)
// 4 - 0123456789     (whole numbers and spaces)
// 5 - 0123456789.    (decimal numbers)
// 6 - 0123456789.-   (decimal numbers and minuses)

var error = "";

switch(numtype){
case 1:
	var strValidChars = "0123456789 -()";
	break;
case 2:
	var strValidChars = "0123456789";
	break;
case 3:
	var strValidChars = "0123456789-";
	break;
case 4:
	var strValidChars = "0123456789 ";
	break;
case 5:
	var strValidChars = "0123456789.";
	break;
case 6:
	var strValidChars = "0123456789.-";
	break;
default :
	var strValidChars = "0123456789";
}

if (required == true) {
	if (formField.length == 0) {
		error = "A " + fielddesc + " is required.\n";
	} else {
		var blnResult = true;
		var strChar;
	
		//  test strString consists of valid characters listed above
		for (i = 0; i < formField.length && blnResult == true; i++)
		  {
		  strChar = formField.charAt(i);
		  if (strValidChars.indexOf(strChar) == -1)
			 {
			 error = "The " + fielddesc + " should only contain '" +  strValidChars + "' characters.\n";
			 }
		}
	}
}
else {
	if (formField.length != 0) {
		var blnResult = true;
		var strChar;
	
		//  test strString consists of valid characters listed above
		for (i = 0; i < formField.length && blnResult == true; i++)
		  {
		  strChar = formField.charAt(i);
		  if (strValidChars.indexOf(strChar) == -1)
			 {
			 error = "The " + fielddesc + " should only contain '" +  strValidChars + "' characters.\n";
			 }
		}
	}
}
return error;
}



// non-empty textbox
function isEmpty(formField, fielddesc, ResponseStarter) {
var error = "";
  if (formField.length == 0) {
	error = ResponseStarter + " " + fielddesc + " is required.\n"
  }
return error;	  
}



// valid selector from dropdown list
function checkDropdown(Choice, fielddesc) {
var error = "";
    if (Choice == "") {
    error = "You didn't choose " + fielddesc + ".\n";
    }    
return error;
}



// valid content for a text box
function checkContent(formField, fielddesc, txtNottoequal, required) {
  var error = "";

  if (required & formField.length == 0) {
     error = "Please enter a " + fielddesc + ".\n";
  } else {
    if (formField == txtNottoequal) {
      Error = "Please enter a " + fielddesc + ".\n";
    }
   }
   return error;
}


// ------------------------------------------------------------------
// Utility functions for parsing in getDateFromFormat()
// ------------------------------------------------------------------
function _isInteger(val) {
	var digits="1234567890";
	for (var i=0; i < val.length; i++) {
		if (digits.indexOf(val.charAt(i))==-1) { return false; }
		}
	return true;
	}

function _getInt(str,i,minlength,maxlength) {
	for (var x=maxlength; x>=minlength; x--) {
		var token=str.substring(i,i+x);
		if (token.length < minlength) { return null; }
		if (_isInteger(token)) { return token; }
		}
	return null;
	}


// -------------------------------------------------------------------
// compareDates(date1,date1format,date2,date2format)
//   Compare two date strings to see which is greater.
//   Returns:
//   1 if date1 is greater than date2
//   0 if date2 is greater than date1 of if they are the same
//  -1 if either of the dates is in an invalid format
// -------------------------------------------------------------------
function compareDates(date1,dateformat1,date2,dateformat2) {
	var d1=getDateFromFormat(date1,dateformat1);
	var d2=getDateFromFormat(date2,dateformat2);
	if (d1==0 || d2==0) {
		return -1;
		}
	else if (d1 > d2) {
		return 1;
		}
	return 0;
	}



// ------------------------------------------------------------------
// getDateFromFormat( date_string , format_string )
//
// This function takes a date string and a format string. It matches
// If the date string matches the format string, it returns the 
// getTime() of the date. If it does not match, it returns 0.
// ------------------------------------------------------------------
function getDateFromFormat(val,format) {
	var MONTH_NAMES=new Array('January','February','March','April','May','June','July','August','September','October','November','December','Jan','Feb','Mar','Apr','May','Jun','Jul','Aug','Sep','Oct','Nov','Dec');

	val=val+"";
	format=format+"";
	var i_val=0;
	var i_format=0;
	var c="";
	var token="";
	var token2="";
	var x,y;
	var now=new Date();
	var year=now.getYear();
	var month=now.getMonth()+1;
	var date=now.getDate();
	var hh=now.getHours();
	var mm=now.getMinutes();
	var ss=now.getSeconds();
	var ampm="";
	
	while (i_format < format.length) {
		// Get next token from format string
		c=format.charAt(i_format);
		token="";
		while ((format.charAt(i_format)==c) && (i_format < format.length)) {
			token += format.charAt(i_format++);
			}
		// Extract contents of value based on format token
		if (token=="yyyy" || token=="yy" || token=="y") {
			if (token=="yyyy") { x=4;y=4; }
			if (token=="yy")   { x=2;y=2; }
			if (token=="y")    { x=2;y=4; }
			year=_getInt(val,i_val,x,y);
			if (year==null) { return 0; }
			i_val += year.length;
			if (year.length==2) {
				if (year > 70) { year=1900+(year-0); }
				else { year=2000+(year-0); }
				}
			}
		else if (token=="MMM"){
			month=0;
			for (var i=0; i<MONTH_NAMES.length; i++) {
				var month_name=MONTH_NAMES[i];
				if (val.substring(i_val,i_val+month_name.length).toLowerCase()==month_name.toLowerCase()) {
					month=i+1;
					if (month>12) { month -= 12; }
					i_val += month_name.length;
					break;
					}
				}
			if ((month < 1)||(month>12)){return 0;}
			}
		else if (token=="MM"||token=="M") {
			month=_getInt(val,i_val,token.length,2);
			if(month==null||(month<1)||(month>12)){return 0;}
			i_val+=month.length;}
		else if (token=="dd"||token=="d") {
			date=_getInt(val,i_val,token.length,2);
			if(date==null||(date<1)||(date>31)){return 0;}
			i_val+=date.length;}
		else if (token=="hh"||token=="h") {
			hh=_getInt(val,i_val,token.length,2);
			if(hh==null||(hh<1)||(hh>12)){return 0;}
			i_val+=hh.length;}
		else if (token=="HH"||token=="H") {
			hh=_getInt(val,i_val,token.length,2);
			if(hh==null||(hh<0)||(hh>23)){return 0;}
			i_val+=hh.length;}
		else if (token=="KK"||token=="K") {
			hh=_getInt(val,i_val,token.length,2);
			if(hh==null||(hh<0)||(hh>11)){return 0;}
			i_val+=hh.length;}
		else if (token=="kk"||token=="k") {
			hh=_getInt(val,i_val,token.length,2);
			if(hh==null||(hh<1)||(hh>24)){return 0;}
			i_val+=hh.length;hh--;}
		else if (token=="mm"||token=="m") {
			mm=_getInt(val,i_val,token.length,2);
			if(mm==null||(mm<0)||(mm>59)){return 0;}
			i_val+=mm.length;}
		else if (token=="ss"||token=="s") {
			ss=_getInt(val,i_val,token.length,2);
			if(ss==null||(ss<0)||(ss>59)){return 0;}
			i_val+=ss.length;}
		else if (token=="a") {
			if (val.substring(i_val,i_val+2).toLowerCase()=="am") {ampm="AM";}
			else if (val.substring(i_val,i_val+2).toLowerCase()=="pm") {ampm="PM";}
			else {return 0;}
			i_val+=2;}
		else {
			if (val.substring(i_val,i_val+token.length)!=token) {return 0;}
			else {i_val+=token.length;}
			}
		}
	// If there are any trailing characters left in the value, it doesn't match
	if (i_val != val.length) { return 0; }
	// Is date valid for month?
	if (month==2) {
		// Check for leap year
		if ( ( (year%4==0)&&(year%100 != 0) ) || (year%400==0) ) { // leap year
			if (date > 29){ return false; }
			}
		else { if (date > 28) { return false; } }
		}
	if ((month==4)||(month==6)||(month==9)||(month==11)) {
		if (date > 30) { return false; }
		}
	// Correct hours value
	if (hh<12 && ampm=="PM") { hh+=12; }
	else if (hh>11 && ampm=="AM") { hh-=12; }
	var newdate=new Date(year,month-1,date,hh,mm,ss);
	return newdate.getTime();
	}


function GetMonth(monthUse){
	var MonthReturn = "";
	
	switch (monthUse) 
	{
	case "Jan":
	  MonthReturn = "01"
	  break
	case "Feb":
	  MonthReturn = "02"
	  break
	case "Mar": 
	  MonthReturn = "03"
	  break
	case "Apr": 
	  MonthReturn = "04"
	  break
	case "May": 
	  MonthReturn = "05"
	  break
	case "Jun": 
	  MonthReturn = "06"
	  break
	case "Jul": 
	  MonthReturn = "07"
	  break
	case "Aug": 
	  MonthReturn = "08"
	  break
	case "Sep": 
	  MonthReturn = "09"
	  break
	case "Oct": 
	  MonthReturn = "10"
	  break
	case "Nov": 
	  MonthReturn = "11"
	  break
	default: 
	  MonthReturn = "12"
	  break
	}
	return MonthReturn;
}


// valid selector from dropdown list
function checkDatesValid(Aday, Amonth, Ayear, Dday, Dmonth, Dyear) {
  var err = "";
  err += checkDropdown(Aday,"an Arrival Day");
  err += checkDropdown(Amonth,"an Arrival Month");
  err += checkDropdown(Ayear,"an Arrival Year");
  err += checkDropdown(Dday,"a Departure Day");
  err += checkDropdown(Dmonth,"a Departure Month");
  err += checkDropdown(Dyear,"a Departure Year");

  if (err == "") {
    var arrDate = "";
    var depDate = "";
    var now = new Date();
    var currentDate = now.getYear().toString() + (now.getMonth()+1).toString() + now.getDate().toString();

    arrDate = Ayear + GetMonth(Amonth) + Aday;
    depDate = Dyear + GetMonth(Dmonth) + Dday;
//err += "Arrival Date = " + arrDate + "\n";
//err += "Departure Date = " + depDate + "\n";
//err += "Current Date = " + currentDate + "\n";

    if (parseInt(arrDate) < parseInt(currentDate)) {
      err += "The arrival date has already passed.\n";
    }

    if (parseInt(depDate) < parseInt(currentDate)) {
      err += "The departure date has already passed.\n";
    }

  }

  if (err == "") {
    var arrDate2 = "";
    var depDate2 = "";
    var compDate = 0;

    // now dates have been checked ... convert them to date format
    arrDate2 = Amonth + " " + Aday + ", " + Ayear;
    depDate2 = Dmonth + " " + Dday + ", " + Dyear;

    // now converted check the departure date is greater or equal to the arrival date
    compDate = compareDates(arrDate2,"MMM d, y",depDate2,"MMM d, y");

    if (compDate == 1) {
      err += "The departure date is before the arrival date.\n";
    }
  }

  return err;
}