function popUpCal()
{
var url = "calendar_flight_maint.php";
var width = 700;
var height = 600;
var left = parseInt((screen.availWidth/2) - (width/2));
var top = parseInt((screen.availHeight/2) - (height/2));
var windowFeatures = "width=" + width + ",height=" + height + ",status,resizable,left=" + left + ",top=" + top + "screenX=" + left + ",screenY=" + top;
window.open(url, "subWind", windowFeatures, "POS", "toolbar=no", "scrollbars=1");
}