function isInteger(s) {
    for (i=0; i<s.length; i++) {
        ch = s.charAt(i);
        if ((ch < '0' || ch > '9') && (ch != '-') && (ch != ' ') && (ch != '.') ) {
            return false;
        }
    }
    return true;
}

function window_pop(url,wwidth,wheight) {
	newWindow = window.open(url,'newWindow','left=50,top=50,resizable=yes,width=' + wwidth + ',height=' + wheight);
}

var curl;

if (navigator.appVersion.indexOf("Mac") != -1 ) { curl = 'mac.css'; }
else if (navigator.appName.indexOf("Microsoft") != -1 ) { curl = 'ie.css'; }
else if (navigator.appName.indexOf("Netscape") != -1 ) { curl = 'ns.css'; }
else { curl = 'main.css'; }
document.write('<link rel="stylesheet" href="css/' + curl + '" type="text/css"></link>');