function goLastMonth(month, year, added_querystring) { 
	// If the month is January, decrement the year 
	if(month == 1) { 
		--year;
		month = 13;
	}
	var currPage = window.location.href.split("?")[0];
	var currPage = currPage.split("#")[0];
	//var currPage = 'index.php'
	document.location.href = currPage + "?month=" + (month-1) + "&year="+year + added_querystring;
}

function goNextMonth(month, year, added_querystring) {
	// If the month is December, increment the year 
	if(month == 12) {
		++year;
		month = 0;
	}
	var currPage = window.location.href.split("?")[0];	// remove current querystring
	var currPage = currPage.split("#")[0];	// remove any anchors
	document.location.href =  currPage + "?month=" + (month+1) + "&year=" + year + added_querystring;
}

function openLargeCal(cat_array) {
	var theURL = 'evtcal_full.php?show_cat=' + cat_array;
	var theWin = window.open(theURL,'evtcalfull');
}