// JavaScript Document

var W3CDOM = (document.getElementsByTagName && document.createElement);

function getElementsByClass(searchClass,node,tag) {
	var classElements = new Array();
	if ( node == null )
		node = document;
	if ( tag == null )
		tag = '*';
	var els = node.getElementsByTagName(tag);
	var elsLen = els.length;
	var pattern = new RegExp("(^|\\s)"+searchClass+"(\\s|$)");
	for (i = 0, j = 0; i < elsLen; i++) {
		if ( pattern.test(els[i].className) ) {
			classElements[j] = els[i];
			j++;
		}
	}
	return classElements;
}

function validate() {
	validForm = true;
	firstError = null;
	errorstring = '';
//	var x = document.forms['query'].elements;
	var x = getElementsByClass('req',document.forms['query']);
	for (var i=0;i<x.length;i++) {
		if (!x[i].value)
			writeError(x[i],'This field is required:');
	}
	if (document.forms['query'].elements['email'].value.indexOf('@') == -1)
		writeError(document.forms['query'].elements['email'],'This is not a valid email address.');
	if (!W3CDOM)
		alert(errorstring);
	if (firstError)
		firstError.focus();
	if (validForm)
		return true;
	return false;
}

function writeError(obj,message) {
	validForm = false;
	if (obj.hasError) return;
	if (W3CDOM) {
		obj.className += ' error';
		obj.onchange = removeError;
		var sp = document.createElement('span');
		sp.className = 'error';
		sp.appendChild(document.createTextNode(message));
		obj.parentNode.insertBefore(sp,obj.previousSibling);
		obj.hasError = sp;
	}
	else {
		errorstring += obj.name + ': ' + message + '\n';
		obj.hasError = true;
	}
	if (!firstError)
		firstError = obj;
}

function removeError() {
	this.className = this.className.substring(0,this.className.lastIndexOf(' '));
	this.parentNode.removeChild(this.hasError);
	this.hasError = null;
	this.onchange = null;
}

window.onload = function () {
	document.forms['query'].onsubmit = validate;
}