var isIE=false;
var isSafari=false;
var isOpera=false;
var isGecko=false;
if(window.ActiveXObject)isIE=true;
else if(document.getSelection&&!window.opera)isGecko=true;
else if(window.getSelection&&window.getSelection().setBaseAndExtent)isSafari=true;
else if(window.opera)isOpera=true;

function _(id) {
	if (document.getElementById(id)) {
		return document.getElementById(id);
	} else {
		return false;
	}
}

function css(a,o,c1,c2) {
	switch (a){
    	case 'swap':
			o.className=!jscss('check',o,c1)?o.className.replace(c2,c1):o.className.replace(c1,c2);
		break;
		case 'add':
			if(!css('check',o,c1)){o.className+=o.className?' '+c1:c1;}
			break;
		case 'remove':
			var rep=o.className.match(' '+c1)?' '+c1:c1;
			o.className=o.className.replace(rep,'');
			break;
		case 'check':
			return new RegExp('\\b'+c1+'\\b').test(o.className)
    	break;
	}
}