function change_tabs(active_tab) {
	switch(active_tab) {
		case "Webseite":
			document.getElementById("spanTab_Webseite").style.background = "#FFF";
			document.getElementById("spanTab_Bearbeiten").style.background = "#e0e0e0";
			document.getElementById("spanTab_History").style.background = "#e0e0e0";

			document.getElementById("layout_bilder").style.display='block';
			document.getElementById("content").style.display='block';
			document.getElementById("edit_tab").style.display='none';
			document.getElementById("history_tab").style.display='none';
			break;
		case "Bearbeiten":
			document.getElementById("spanTab_Webseite").style.background = "#e0e0e0";
			document.getElementById("spanTab_Bearbeiten").style.background = "#FFF";
			document.getElementById("spanTab_History").style.background = "#e0e0e0";

			document.getElementById("layout_bilder").style.display='none';
			document.getElementById("content").style.display='none';
			document.getElementById("edit_tab").style.display='block';
			document.getElementById("history_tab").style.display='none';
			break;
		case "History":
			document.getElementById("spanTab_Webseite").style.background = "#e0e0e0";
			document.getElementById("spanTab_Bearbeiten").style.background = "#e0e0e0";
			document.getElementById("spanTab_History").style.background = "#FFF";

			document.getElementById("layout_bilder").style.display='none';
			document.getElementById("content").style.display='none';
			document.getElementById("edit_tab").style.display='none';
			document.getElementById("history_tab").style.display='block';
			break;
		default:
			document.getElementById("spanTab_Webseite").style.background = "#FFF";
			document.getElementById("spanTab_Bearbeiten").style.background = "#e0e0e0";
			document.getElementById("spanTab_History").style.background = "#e0e0e0";

			document.getElementById("layout_bilder").style.display='block';
			document.getElementById("content").style.display='block';
			document.getElementById("edit_tab").style.display='none';
			document.getElementById("history_tab").style.display='none';
			break;
	}
}