function atl_htmldocumentclass(){

	this.getChildrenNodes = function (tag, tagtype){
		var subtagslist = tag.getElementsByTagName(tagtype);
		var childrenNodes = [];
		for (i = 0; i < subtagslist.length; i++){
			if (subtagslist[i].parentNode == tag) {
				childrenNodes.push(subtagslist[i]);
			}
		}
		return childrenNodes;
	}
}

function showelement(id){
	var myelement = document.getElementById(id);
	myelement.style.visibility = 'visible';
}

function hiddeelement(id){
	var myelement = document.getElementById(id);
	myelement.style.visibility = 'hidden';
}

function isValidEmail(str) {
		return (str.indexOf(".") > 2) && (str.indexOf("@") > 0);
}