function showTab(id,number) {
	var tab = true; var button = true;
	var i = 1;
	while (tab) {
		tab = document.getElementById('ctn_'+id+'_tab'+i);
		button = document.getElementById('btn_'+id+'_tab'+i);

		if (tab) {
			if( i != number ) {
				tab.className="tab_hidden";
				button.className="";
			}
			else {
				tab.className="tab";
				button.className="active";
			}
		}
		i++;
	}
}