function changeTab(id)
{
	if (id == 0) { 
		document.getElementById("content_overview").style.display = "block";
		document.getElementById("content_specifications").style.display = "none";
		document.getElementById("content_technology").style.display = "none";
		document.getElementById("overview").className = "content_tab_selected";
		document.getElementById("specifications").className = "content_tab";
		document.getElementById("technology").className = "content_tab";
	} else if (id == 1)	{ 
		document.getElementById("content_overview").style.display = "none";
		document.getElementById("content_specifications").style.display = "block";
		document.getElementById("content_technology").style.display = "none";
		document.getElementById("overview").className = "content_tab";
		document.getElementById("specifications").className = "content_tab_selected";
		document.getElementById("technology").className = "content_tab";
	} else if (id == 2)	{ 
		document.getElementById("content_overview").style.display = "none";
		document.getElementById("content_specifications").style.display = "none";
		document.getElementById("content_technology").style.display = "block";
		document.getElementById("overview").className = "content_tab";
		document.getElementById("specifications").className = "content_tab";
		document.getElementById("technology").className = "content_tab_selected";
	}
}