// Open a popup window
function popupWindow(url, windowHeight, windowWidth) {

    // How big is the window gonna be?
    if (!windowHeight) windowHeight = 400;
    if (!windowWidth)  windowWidth  = 600;

    // Avoid making the popup larger than the user's screen
    if (windowHeight>screen.availHeight) windowHeight = screen.availHeight;
    if (windowWidth>screen.availWidth) windowWidth = screen.availWidth;

    // Position the window in the middle of the screen
    fromTop  = (screen.availHeight-windowHeight)/2;
    fromLeft = (screen.availWidth-windowWidth)/2;

    newWindow = window.open(url, 'sw_popup', 'height='+ windowHeight +', width='+windowWidth+', top='+fromTop+', left='+fromLeft+', dependent=no, directories=no, location=no, menubar=no, resizable=yes, scrollbars=yes, status=yes, toolbar=no');
    
	if (window.focus) { 
    
    if (!newWindow) return true;
    else newWindow.focus();
    
    }
    
    return false;

}


function createCookie(name,value,days) {
	if (days) {
		var date = new Date();
		date.setTime(date.getTime()+(days*24*60*60*1000));
		var expires = "; expires="+date.toGMTString();
	}
	else var expires = "";
	document.cookie = name+"="+value+expires+"; path=/";
}

function readCookie(name) {
	var nameEQ = name + "=";
	var ca = document.cookie.split(';');
	for(var i=0;i < ca.length;i++) {
		var c = ca[i];
		while (c.charAt(0)==' ') c = c.substring(1,c.length);
		if (c.indexOf(nameEQ) == 0) return c.substring(nameEQ.length,c.length);
	}
	return null;
}

function eraseCookie(name) {
	createCookie(name,"",-1);
}