var buildDir = "js/";
var mywidth;

if (screen.width >= 1152) {
 document.write('<script type="text/javascript" src="' + buildDir + 'config1152.js"></script>');
}
else if (screen.width >= 1024) {
 document.write('<script type="text/javascript" src="' + buildDir + 'config1024.js"></script>');
}
else if (screen.width <= 800){
 document.write('<script type="text/javascript" src="' + buildDir + 'config.js"></script>');
}

mywidth = screen.width;