// Date Validation Javascript
// copyright 30th October 2004, by Stephen Chapman
// http://javascript.about.com

// You have permission to copy and use this javascript provided that
// the content of the script is not changed in any way.

function valDateFmt(datefmt) {
	myOption = -1;
	for (i=0; i<datefmt.length; i++) {
		if (datefmt[i].checked) {
			myOption = i;
		}
	}

	if (myOption == -1) {
		alert("You must select a date format");return ' ';
	}

	return datefmt[myOption].value;
}

function valDateRng(daterng) {
	myOption = -1;
	for (i=0; i<daterng.length; i++) {
		if (daterng[i].checked) {
			myOption = i;
		}
	}

	if (myOption == -1) {
		alert("You must select a date range");
		return ' ';
	}
	return daterng[myOption].value;
}

function stripBlanks(fld) {
	var result = "";
	for (i=0; i<fld.length; i++) {
		if (fld.charAt(i) != " " || c > 0) {
			result += fld.charAt(i);
			if (fld.charAt(i) != " ") c = result.length;
		}
	}
	return result.substr(0,c);
}
var numb = '0123456789';

function isValid(parm,val) {
	if (parm == "") return true;
	for (i=0; i<parm.length; i++) {
		if (val.indexOf(parm.charAt(i),0) == -1) return false;
	}
	return true;
}

function isNum(parm) {
	return isValid(parm,numb);
}

var mth = new Array('','january','february','march','april','may','june','july','august','september','october','november','december');
var day = new Array(31,28,31,30,31,30,31,31,30,31,30,31);
//fld = date to be checked
//fmt = format: 'U'=mm/dd/yyyy; 'J'=yyyy/mm/dd; 'W'=dd/mm/yyyy
//rng = Range: 'P'=Past; 'F'=Future; 'A'=Any
function validateDate(fld,fmt,rng) {
	var dd, mm, yy;
	var today = new Date;
	var t = new Date;
	fld = stripBlanks(fld);
	if (fld == '') return false;
	var d1 = fld.split('\/');
	if (d1.length != 3) d1 = fld.split(' ');
	if (d1.length != 3) return false;

	if (fmt == 'u' || fmt == 'U') {
  		dd = d1[1]; mm = d1[0]; yy = d1[2];
	}else if (fmt == 'j' || fmt == 'J') {
  		dd = d1[2]; mm = d1[1]; yy = d1[0];
	}else if (fmt == 'w' || fmt == 'W'){
  		dd = d1[0]; mm = d1[1]; yy = d1[2];
	}else return false;

	var n = dd.lastIndexOf('st');
	if (n > -1) dd = dd.substr(0,n);
	n = dd.lastIndexOf('nd');
	if (n > -1) dd = dd.substr(0,n);
	n = dd.lastIndexOf('rd');
	if (n > -1) dd = dd.substr(0,n);
	n = dd.lastIndexOf('th');
	if (n > -1) dd = dd.substr(0,n);
	n = dd.lastIndexOf(',');
	if (n > -1) dd = dd.substr(0,n);
	n = mm.lastIndexOf(',');
	if (n > -1) mm = mm.substr(0,n);
	if (!isNum(dd)) return false;
	if (!isNum(yy)) return false;

	if (!isNum(mm)) {
  		var nn = mm.toLowerCase();
  		for (var i=1; i < 13; i++) {
    			if (nn == mth[i] || nn == mth[i].substr(0,3)) {
				mm = i; i = 13;
			}
  		}
	}

	if (!isNum(mm)) return false;
	dd = parseFloat(dd); 
	mm = parseFloat(mm); 
	yy = parseFloat(yy);
	if (yy < 100) yy += 2000;
	if (yy < 1582 || yy > 4881) return false;
	if (mm == 2 && (yy%400 == 0 || (yy%4 == 0 && yy%100 != 0))) day[mm-1]++;
	if (mm < 1 || mm > 12) return false;
	if (dd < 1 || dd > day[mm-1]) return false;
	t.setDate(dd); 
	t.setMonth(mm-1); 
	t.setFullYear(yy);

	if (rng == 'p' || rng == 'P') {
		if (t > today) return false;
	}else if (rng == 'f' || rng == 'F') {
		if (t < today) return false;
	}else if (rng != 'a' && rng != 'A') return false;
	return true;
}

function dateAdd( start, interval, number ) {
	
    // Create 3 error messages, 1 for each argument. 
    var startMsg = "Sorry the start parameter of the dateAdd function\n"
        startMsg += "must be a valid date format.\n\n"
        startMsg += "Please try again." ;
		
    var intervalMsg = "Sorry the dateAdd function only accepts\n"
        intervalMsg += "d, h, m OR s intervals.\n\n"
        intervalMsg += "Please try again." ;

    var numberMsg = "Sorry the number parameter of the dateAdd function\n"
        numberMsg += "must be numeric.\n\n"
        numberMsg += "Please try again." ;
		
    // get the milliseconds for this Date object. 
    var buffer = Date.parse( start ) ;
	
    // check that the start parameter is a valid Date. 
    if ( isNaN (buffer) ) {
        alert( startMsg ) ;
        return null ;
    }
	
    // check that an interval parameter was not numeric. 
    if ( interval.charAt == 'undefined' ) {
        // the user specified an incorrect interval, handle the error. 
        alert( intervalMsg ) ;
        return null ;
    }

    // check that the number parameter is numeric. 
    if ( isNaN ( number ) )	{
        alert( numberMsg ) ;
        return null ;
    }

    // so far, so good...
    //
    // what kind of add to do? 
    switch (interval.charAt(0))
    {
        case 'd': case 'D': 
            number *= 24 ; // days to hours
            // fall through! 
        case 'h': case 'H':
            number *= 60 ; // hours to minutes
            // fall through! 
        case 'm': case 'M':
            number *= 60 ; // minutes to seconds
            // fall through! 
        case 's': case 'S':
            number *= 1000 ; // seconds to milliseconds
            break ;
        default:
        // If we get to here then the interval parameter
        // didn't meet the d,h,m,s criteria.  Handle
        // the error. 		
        alert(intervalMsg) ;
        return null ;
    }
    return new Date( buffer + number ) ;
}