I am sending a request to ajax/matchreport.php along with the attribute ?minute=x when the request comes back i want it to add 1 to the minute and then resend so:

ajax/matchreport.php?minute=0
ajax/matchreport.php?minute=1

Using this code the first time the request does it correct then it enters NaN instead of a number after minutes

ajax/matchreport.php?minute=0
ajax/matchreport.php?minute=NaN

Any ideas??

<script language="javascript" type="text/javascript">
<!-- 
function MatchController(match_id) {
this.match_id = match_id;
this.minute = Number(0);
}
MatchController.setMinute = function(minute) {
minute = Number(minute);
this.minute = (minute - 1) + 1;

MatchController.setGame();

}
MatchController.setGame = function() {
// Display Loading Image
document.getElementById('loading').innerHTML="<img src='images/css/ajax-loader.gif' class='noimg' /> Playing Match";
    var ajaxRequest;  // The variable that makes Ajax possible!
    try{
        // Opera 8.0+, Firefox, Safari
        ajaxRequest = new XMLHttpRequest();
    } catch (e){
        // Internet Explorer Browsers
        try{
            ajaxRequest = new ActiveXObject("Msxml2.XMLHTTP");
        } catch (e) {
            try{
                ajaxRequest = new ActiveXObject("Microsoft.XMLHTTP");
            } catch (e){
                // Something went wrong
                alert("Your Browser Does Not Support Ajax/Javascript!");
                return false;
            }
        }
    }
    // Create a function that will receive data sent from the server
    ajaxRequest.onreadystatechange = function(){
        if(ajaxRequest.readyState == 4){
// Hide Loading Image Then Re Send The Function If Minutes Under 90
document.getElementById('loading').innerHTML="";
MatchController.setMinute(this.minute);
}
}
    var queryString = "?minute=" + Number(this.minute);
    ajaxRequest.open("GET", "ajax/matchreport.php" + queryString, true);
    ajaxRequest.send(null);
}

</script>

You will need to recode it to use a "reusable" request object then use a setInterval() loop to call the function.