function $(id){
	return document.getElementById(id);
}
function $v(id){
	if($(id)) return $(id).value;
	else return null;
}
function $Clear(id){
	if($(id)) $v(id) = "";
}
function $Show(id){
	if($(id)) $(id).style.display = "block";
}
function $Hide(id){
	if($(id)) $(id).style.display = "none";
}
function $ShowHide(ids, idh){
	if($(idh)) $(idh).style.display = "none";	
	if($(ids)) $(ids).style.display = "block";
}
function $ShowHideTR(ids, idh){
	if($(idh)) $(idh).style.display = "none";	
	if($(ids)) $(ids).style.display = "table-row";
}
function $wGo(url){
	window.location = url;
}
function is_empty(str){
	if(str == null) return false;
	return str.match(/^\s*$/g);
}
function is_email(email){
	var regex=/^([\w-]+(?:\.[\w-]+)*)@((?:[\w-]+\.)*\w[\w-]{0,66})\.([a-z]{2,6}(?:\.[a-z]{2})?)$/i
	if(regex.test(email)) return true;
	else return false;
}