function changePage(mySource) {
			var baseURL = "http://www.fb1.uni-siegen.de";
			var target = document.forms.navi.elements[mySource].options[document.forms.navi.elements[mySource].options.selectedIndex].value;
			if (target != 'invalid') {
				if (target.substr(0,4) == 'http') {
					window.location.href=target;
				}
				else {
					window.location.href=baseURL+target;
				}
			}
		}