function ClientChecker () {

  	// Opera 8.0+
	var isOpera = (!!window.opr && !!opr.addons) || !!window.opera || navigator.userAgent.indexOf(' OPR/') >= 0;

	// Firefox 1.0+
	var isFirefox = typeof InstallTrigger !== 'undefined';

	// Safari 3.0+ "[object HTMLElementConstructor]" 
	var isSafari = /constructor/i.test(window.HTMLElement) || (function (p) { return p.toString() === "[object SafariRemoteNotification]"; })(!window['safari'] || (typeof safari !== 'undefined' && 		safari.pushNotification));

	// Internet Explorer 6-11
	var isIE = /*@cc_on!@*/false || !!document.documentMode;

	// Edge 20+
	var isEdge = !isIE && !!window.StyleMedia;

	// Chrome 1+
	var isChrome = !!window.chrome && !!window.chrome.webstore;

	// Blink engine detection
	var isBlink = (isChrome || isOpera) && !!window.CSS;


	var enableDB = !isSafari;

	console.log ("is client okay for db = " + enableDB);

	return !enableDB; //return reversed bool so we can disable cache xml request

}