func

<script>
function ajax(var func){
    var xmlhttp;
    if (window.XMLHttpRequest){ // code for IE7+, Firefox, Chrome, Opera, Safari
        xmlhttp=new XMLHttpRequest();
    }
    else{ // code for IE6, IE5
        xmlhttp=new ActiveXObject("Microsoft.XMLHTTP");
    }
    xmlhttp.onreadystatechange=function(){
        if (xmlhttp.readyState==4 && xmlhttp.status==200){
            document.getElementById("calendar").innerHTML=xmlhttp.responseText;
        }
    }
    if(func=='p'){
        var pyear = document.getElementById("pyear").innerHTML;
        var pmonth = document.getElementById("pmonth").innerHTML;
        xmlhttp.open("GET","calendar.php?y=" + pyear + "&m=" + pmonth,true);
    }else if(func=='n'){
        var nyear = document.getElementById("nyear").innerHTML;
        var nmonth = document.getElementById("nmonth").innerHTML;
        xmlhttp.open("GET","calendar.php?y=" + nyear + "&m=" + nmonth,true);
    }
    xmlhttp.send();
}

</script>