function openWindow( ) {
	try{
		plattformWindow.focus();
	}catch(e){
		var js_startroot = "http://zinal.learning-suite.de/management/loginCenter/index.cfm";
		var offsetY = Math.max( 0, parseInt( ( screen.availHeight - 653 ) / 2 ) );
		var offsetX = Math.max( 0, parseInt( ( screen.availWidth - 991 ) / 2 ) );
		plattformWindow = window.open( js_startroot , 'plattform_1','resizable=yes toolbar=no,statusbar=no,location=no,scrollbars=auto,menubar=no,top=' + offsetY + ',left=' + offsetX + ',height=' + 653 + ',width=' + 991 );
		plattformWindow.focus();
	}
};