// Generic Form Validation
// Eugen Fleseriu
var checkObjects	= new Array();
var errors			= "";
var returnVal		= false;
var language		= new Array();
language["header"]	= "The following error(s) occurred:"
language["start"]	= "->";
language["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"]	= " character(s)";
language["num"]		= " and must contain a number";
language["email"]	= " must contain a valid e-mail address";
language["combo"]	= " must select an option";
language["exact"]	= " and must consist of exactly ";
// -----------------------------------------------------------------------------
// 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;
	x= d[n];
	if (!x && 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()
{
	var i, validateObject;
	if (checkObjects.length> 0)
	{
		for (i= 0; i< checkObjects.length; i++)
		{
			validateObject= new Object();
			validateObject.form= checkObjects[i].form;
			validateObject.type= checkObjects[i].type;
			validateObject.HTMLname= checkObjects[i].HTMLname;
			if (validateObject.type== "combo")
			{
				if (navigator.appName== "Netscape")
					validateObject.val= new String(checkObjects[i].form.selectedIndex);
				else
					validateObject.val= new String(checkObjects[i].form.value);
			}
			else
				validateObject.val= new String(checkObjects[i].form.value);
			validateObject.len= validateObject.val.length;
			validateObject.min= checkObjects[i].min;
			validateObject.max= checkObjects[i].max;
			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'];
					if (validateObject.min!= validateObject.max)
					errors+= language['min']+ validateObject.min+ language['minmax']+ validateObject.max+ language['chars']+ "\n";
					else
					errors+= language['exact']+ validateObject.min+ 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== "combo")
			{
				if ((validateObject.val== "0") ||
					(validateObject.len< 1))
					errors+= language['start'] + language['field'] + validateObject.HTMLname + language['combo'] + "\n";
			}
		}
		if (errors)
		{
			alert(language["header"]+ "\n" + errors);
			errors= "";
			returnVal= false;
		}
		else
		{
			returnVal= true;
		}
	}
}