You don't need thread programming to do that in javascript. You nead timing events:
http://www.w3schools.com/js/js_timing.asp
and to use objects of type date:
http://www.w3schools.com/jsref/jsref_obj_date.asp
you can implement something similar to this code that I've written:
<script type="text/javascript">
var mins_alert=10;
function alert_func(){
alert("in "+mins_alert+" minutes you will have an appointment!");
caller();
}
function caller(){
//get the current date
var now = new Date();
//get the next event (these values should come from a database or somewhere, and be update each time that the caller function is run...)
var month_str="february";
var day=28;
var year=2013;
var hours=22;
var mins=57;
var secs=0;
var next_event = new Date(month_str+day+", "+year+" "+hours+":"+mins+":"+secs);
// alert("now:\n"+now);
// alert("next_event:\n"+next_event);
var delta_millisecs = next_event.getTime()-now.getTime(); //difference, in milliseconds, between these the current date and the date of the next appointment
var delta_t = delta_millisecs-mins_alert*60*1000; //number of milliseconds between now to the alert event
if (delta_t>0){
setTimeout("alert_func()", delta_t);
}
}
</script>
Hope that helps!
