var tabs = new Array('tab1', 'tab2');

function activateTab(tab)
{
	for (i = 0; i < tabs.length; i++)
	{
		if (document.getElementById(tabs[i]))
		{
			document.getElementById(tabs[i]).style.display = 'none';
			document.getElementById('link_' + tabs[i]).className= 'disabled_link_' + tabs[i];
		}
	}
	document.getElementById(tab).style.display = 'block';
	document.getElementById('link_' + tab).className= 'active_link_' + tab;
}