Im wondering if its possible to call a file when the resize window match on the set variable,, do you think its possible in the codes below? it can call a php file but it will need to take a refresh just to call the another file..

PHP Code:
<!DOCTYPE html>
<
html>

<
head>
<
script type="text/javascript" src="http://code.jquery.com/jquery-1.8.3.min.js"></script>


<
script>

var 
= $(window).width();

if(
a>=970){

    $.
get("970x250.php",
    {
    
//ads: "getrssfeeds",//source: 8,//site: 2584,//limit: 5,
    
},

    function(
data){
    $(
"body").append(data);
        }
    );
}    
else if(
a>=320){
    $.
get("970x90.php",
    {
    
//ads: "getrssfeeds",//source: 8,//site: 2584,//limit: 5,
    
},

    function(
data){
    $(
"body").append(data);
        }
    );
}


</
script>
</
head>

<
body>




</
body>
</
html