var userAgent = navigator.userAgent.toLowerCase();
var browser = {
	safari: /webkit/.test(userAgent),
	opera: /opera/.test(userAgent),
	msie: /msie/.test(userAgent) && !/opera/.test(userAgent),
	mozilla: /mozilla/.test(userAgent) && !/(compatible|webkit)/.test(userAgent)
};

var initLayout = function() {
	if (browser.safari) {
		document.body.className += ' safari';
	}

	var mainM = document.getElementById('mainM');
	mainM.style.height = Math.max(mainM.parentNode.offsetHeight - 57, 0) + 'px';

}
window.onload = initLayout;