function $() {
    var elems = [];
    for (var i=0; i<arguments.length; i++) {
        var elem = arguments[i];
        if (typeof elem == 'string') elem = document.getElementById(elem);
        if (arguments.length == 1) return elem;
        elems.push(elem);
    }
    return elems;
}
Object.prototype.$T = function (t,o) {   
	o = o || document;
    return o.getElementsByTagName(t);
}
var requirementsSwap = {
	init : function()
		{
		var c = requirementsSwap;
		var oMac = $('req-switcher-mac');
		var oPc = $('req-switcher-pc');
		addEventToObject(oMac,'onclick',function(){c.swap('mac')});
		addEventToObject(oPc,'onclick',function(){c.swap('pc')});
		},
	swap : function(sType)
		{
		var c = requirementsSwap;
		var oSwitcher = $('req-switcher');
		var oMacList = $('req-mac');
		var oPcList = $('req-pc');
		if (sType == 'mac')
			{
			oSwitcher.className = 'mac';
			oMacList.className = '';
			oPcList.className = 'hide';
			}
		else if (sType == 'pc')
			{
			oSwitcher.className = 'pc';
			oMacList.className = 'hide';
			oPcList.className = '';
			}
		}
	};
//addEventToObject(window,'onload',requirementsSwap.init);