You need to use ajax. There is a basic example:
myscripts.js
function AjaxCaller(){
var xmlhttp=false;
try{
xmlhttp = new ActiveXObject("Msxml2.XMLHTTP");
}catch(e){
try{
xmlhttp = new ActiveXObject("Microsoft.XMLHTTP");
}catch(E){
xmlhttp = false;
}
}
if(!xmlhttp && typeof XMLHttpRequest!='undefined'){
xmlhttp = new XMLHttpRequest();
}
return xmlhttp;
}
function callPage(url, div){
ajax=AjaxCaller();
ajax.open("GET", url, true);
ajax.onreadystatechange=function(){
if(ajax.readyState==4){
if(ajax.status==200){
div.innerHTML = ajax.responseText;
}
}
}
ajax.send(null);
}
function check_year_event(year_id, event_id) {
var year = document.getElementById(year_id).value;
var event = document.getElementById(event_id).value;
callPage('file.php?year='+year+'&'+'event=+'+event,document.getElementById(targetId));
}
file.php
0) {
// do this
}
}
echo checkYearandEvent($_GET['year'], $_GET['event']);
?>