var newWin = '';


// isResizable [0|1]; isScrollable [0|1]
// ex: width=400,height=500,menubar=0,location=0,resizable=1,scrollbars=1
function open_window(url, w, h, isResizable, isScrollable) {
    
    x = (640 - w)/2;
    y = (480 - h)/2;

    if (screen) {
        y = (screen.availHeight - h)/2;
        x = (screen.availWidth - w)/2;
    }
    
    var args = "width=" + w + ",height=" + h + ",menubar=0,location=0,resizable=" + isResizable + ",scrollbars=" + isScrollable+ ",screenX=" + x + ",screenY=" + y + ",top=" + y + ",left=" + x;
	
	if (!newWin.closed && newWin.location) {
		newWin.location.href = url;
	}
	else {	
	    newWin = window.open(url, "newWin", args);
	    if (!newWin.opener) newWin.opener = self;
    }

	if (window.focus) {newWin.focus()}
	//return false;
}