// Form validation script

// A utility function that returns true if a string contains only 
// whitespace characters.
function isblank(s)
{
	for(var i = 0; i < s.length; i++) {
		var c = s.charAt(i);
		if ((c != ' ') && (c != '\n') && (c != '\t')) return false;
	}
	return true;
}

// Check to see if a string contains any non numeric characters

function nonNum(s) {
	for(var i = 0; i < s.length; i++) {
		var c = s.charAt(i);
		var numeric = false
		for(var k = 0; k < 10; k++)
			if (k == c) numeric = true;
		
		if (numeric == false && c != " ") return true;
	}
	
	return false;
}


// This is the function that performs form verification.  It will be invoked
// from the onSubmit() event handler.  The handler should return whatever
// value this function returns.
// usage: verify(document.nameofform);
// NB. make sure that the names of the elements are correct, otherwise it
// will not perform the validation.
function verify(f)
{
	var msg;
	var empty_fields = "";
	var errors = "";

	// Loop through the elements of the form, looking for all 
	// text and textarea elements that don't have an "optional" property
	// defined.  Then, check for fields that are empty and make a list of them.
	// Also, if any of these elements have a "min" or a "max" property defined,
	// then verify that they are numbers and that they are in the right range.
	// Put together error messages for fields that are wrong.
	for(var i = 0; i < f.length; i++) {
		var e = f.elements[i];
		var ename;
		
		// Get actual name
		if (e.actname == "" || e.actname == null) ename = e.name;
		else ename = e.actname;
		
		if (((e.type == "text") || (e.type == "textarea") || (e.type == "select-one") || (e.type == "checkbox")) && (!e.optional)) {
			// first check if the field is empty
			if (e.type == "select-one" && document.layers) {
			
				var opIndex = e.selectedIndex;
				
				if(e.options[opIndex].value == null || e.options[opIndex].value == "") {
						empty_fields += ", " + ename;
						continue;
				
				} else continue;		
				
			} else if ((e.value == null) || (e.value == "") || isblank(e.value)) {
				empty_fields += ", " + ename;
				continue;
			}

			// check for valid email address
			if (e.email || (e.value == null) || (e.value == "")) {
				if (e.value.indexOf('@') < 0)
					errors += "The field '" + ename + "' must be a valid email address.\n";
				continue;
			}

			// Now check for fields that are supposed to be numeric.
			if (e.numeric || (e.min != null) || (e.max != null)) { 
				var v = e.value;
				if (nonNum(v) || 
					((e.min != null) && (v < e.min)) || 
					((e.max != null) && (v > e.max))) {
					errors += "The field '" + ename + "' must be a numerical value";
					if (e.min != null) 
						errors += " that is greater than " + e.min;
					if (e.max != null && e.min != null) 
						errors += " and less than " + e.max;
					else if (e.max != null)
						errors += " that is less than " + e.max;
					errors += ".\n";
				}
			}
		}
	}

	// Now, if there were any errors, then display the messages, and
	// return true to prevent the form from being submitted.  Otherwise
	// return false
	if (!empty_fields && !errors) return true;

	msg  = "Sorry, some of the information we need is incorrect. Please go back and try again.\n\n";
	if (empty_fields) {
		empty_fields = empty_fields.substr(1);
		msg += "The following required field(s) are empty;\n\n" 
			+ empty_fields + "\n\n";
		if (errors) msg += "";
	}
	msg += errors;
	alert(msg);
	return false;
}

// The following function counts all the check boxes with
// the same name and makes sure there are more checked then
// the num variable is set to.
// usage: countCheckBoxes(thisform,'brochureIDs',3);
function countCheckBoxes(f,tocheck,num)
{
	var msg;
	var empty_fields = '';
	var errors = '';
	var count = 0;
	for(var i = 0; i < f.length; i++) {
		var e = f.elements[i];
		if ((e.type == 'checkbox') && (e.name == tocheck) && (e.checked)) {
			count++;
		}
	}
	if (count > num) {
		errors += 'You can only select a maximum of three brochures.\n';
	}
	if (count <= 0) {
		errors += 'You have to select at least one brochure.\n';
	}
	// Now, if there were any errors, then display the messages, and
	// return true to prevent the form from being submitted.  Otherwise
	// return false
	if (!empty_fields && !errors) return true;
	msg = 'Please go back and try again.\n';
	msg += errors;
	alert(msg);
}

function performValidate()
{
}