// Generic Form Validation
// Jacob Hage (jacob@hage.dk)
var checkObjects	= new Array();
var errors		= "";
var returnVal		= false;
var language		= new Array();
language["header"]	= "The following error(s) occured:"
language["start"]	= "->";
language["field"]	= " Field ";
language["require"]	= " is required";
language["min"]		= " and must consist of at least ";
language["max"]		= " and must not contain more than ";
language["minmax"]	= " and no more than ";
language["chars"]	= " characters";
language["num"]		= " and must contain a number";
language["email"]	= " must contain a valid e-mail address";
language["date"]	= " must contain a valid date (mm/dd/yyyy)";
language["dateMin"]	= " and must be after ";
language["dateMax"]	= " and must be before ";
// -----------------------------------------------------------------------------
// define - Call this function in the beginning of the page. I.e. onLoad.
// n = name of the input field (Required)
// type= string, num, email (Required)
// min = the value must have at least [min] characters (Optional)
// max = the value must have maximum [max] characters (Optional)
// d = (Optional)
// -----------------------------------------------------------------------------
function define(n, type, HTMLname, min, max, d) {
	var p;
	var i;
	var x;
	if (!d) d = document;
	if ((p=n.indexOf("?"))>0&&parent.frames.length) {
		d = parent.frames[n.substring(p+1)].document;
		n = n.substring(0,p);
	}
	if (!(x = d[n]) && d.all) x = d.all[n];
	for (i = 0; !x && i < d.forms.length; i++) {
		x = d.forms[i][n];
	}
	for (i = 0; !x && d.layers && i < d.layers.length; i++) {
		x = define(n, type, HTMLname, min, max, d.layers[i].document);
		return x;       
	}
	eval("V_"+n+" = new formResult(x, type, HTMLname, min, max);");
	checkObjects[eval(checkObjects.length)] = eval("V_"+n);
}
	
function formResult(form, type, HTMLname, min, max) {
	this.form = form;
	this.type = type;
	this.HTMLname = HTMLname;
	this.min  = min;
	this.max  = max;
}

function validate() {
	if (checkObjects.length > 0) {
		errorObject = "";
		for (i = 0; i < checkObjects.length; i++) {
			validateObject = new Object();
			validateObject.form = checkObjects[i].form;
			validateObject.HTMLname = checkObjects[i].HTMLname;
			validateObject.val = checkObjects[i].form.value;
			validateObject.len = checkObjects[i].form.value.length;
			validateObject.min = checkObjects[i].min;
			validateObject.max = checkObjects[i].max;
			validateObject.type = checkObjects[i].type;
			if (validateObject.type == "num" || validateObject.type == "string") {
				if ((validateObject.type == "num" && validateObject.len <= 0) || (validateObject.type == "num" && isNaN(validateObject.val))) { errors += language['start'] + language['field'] + validateObject.HTMLname + language['require'] + language['num'] + "\n";
				} else if (validateObject.min && validateObject.max && (validateObject.len < validateObject.min || validateObject.len > validateObject.max)) { errors += language['start'] + language['field'] + validateObject.HTMLname + language['require'] + language['min'] + validateObject.min + language['minmax'] + validateObject.max+language['chars'] + "\n";
				} else if (validateObject.min && !validateObject.max && (validateObject.len < validateObject.min)) { errors += language['start'] + language['field'] + validateObject.HTMLname + language['require'] + language['min'] + validateObject.min + language['chars'] + "\n";
				} else if (validateObject.max && !validateObject.min &&(validateObject.len > validateObject.max)) { errors += language['start'] + language['field'] + validateObject.HTMLname + language['require'] + language['max'] + validateObject.max + language['chars'] + "\n";
				} else if (!validateObject.min && !validateObject.max && validateObject.len <= 0) { errors += language['start'] + language['field'] + validateObject.HTMLname + language['require'] + "\n";
				}
			} else if(validateObject.type == "email") {
				// Checking existense of "@" and ".". 
				// Length of must >= 5 and the "." must 
				// not directly precede or follow the "@"
				if ((validateObject.val.indexOf("@") == -1) || (validateObject.val.charAt(0) == ".") || (validateObject.val.charAt(0) == "@") || (validateObject.len < 6) || (validateObject.val.indexOf(".") == -1) || (validateObject.val.charAt(validateObject.val.indexOf("@")+1) == ".") || (validateObject.val.charAt(validateObject.val.indexOf("@")-1) == ".")) {
					errors += language['start'] + language['field'] + validateObject.HTMLname + language['email'] + "\n"; 
				}
			} else if(validateObject.type == "date") {
				//Expecting date to be in mm/dd/yyyy format, else invalid
				var today = new Date();
				var field = new Date();
				field.setYear( validateObject.val.split("/")[2] );
				field.setMonth( validateObject.val.split("/")[0] - 1 );
				field.setDate( validateObject.val.split("/")[1] );
				if ( ! field.getTime () > 0 ) {
					errors += language['start'] + language['field'] + validateObject.HTMLname + language['date'] + "\n"; 
				}
				if ( validateObject.min ) {
					var minDate = new Date( today.getTime() + validateObject.min * 86400000 );
					var minDateString = (minDate.getMonth()+1) + "/" + minDate.getDate() + "/" + (minDate.getYear()+1900)
					if ( minDate.getTime() > field.getTime() ) {
						errors += language['start'] + language['field'] + validateObject.HTMLname + language['date'] + language['dateMin'] + minDateString + "\n"; 
					}
				}
				if ( validateObject.max ) {
					var maxDate = new Date( today.getTime() + validateObject.max * 86400000 );
					var maxDateString = (maxDate.getMonth()+1) + "/" + maxDate.getDate() + "/" + (maxDate.getYear()+1900)
					if ( maxDate.getTime() < field.getTime() ) {
						errors += language['start'] + language['field'] + validateObject.HTMLname + language['date'] + language['dateMax'] + maxDateString + "\n"; 
					}
				}
			}
		}
	}	
	if (errors) {
		alert(language["header"].concat("\n" + errors));
		errors = "";
		return false;
	} else {
		return true;
	}
	return false;
}