function setActiveTab(tab_id) {
	var i = 0;
	var foundTab = true;
	
	while (foundTab && i < 50) {
		var div = document.getElementById('tab_body_' + i);
		
		if (div == null)
			break;
			
		// get associated header
		var tab = document.getElementById('tab_' + i);
		
		if (i == tab_id) {
			div.style.display = '';
			tab.className = 'tabActive';
		}
		else {
			div.style.display = 'none';
			tab.className = 'tabInactive';
		}
			
		i++;
	}
}