function ShowLoader() {
    $('#loader').css({
        top: getPageScroll()[1] + (getPageHeight() / 10),
        left: ($(window).width() - $('#loader').width()) / 2
    });
    $('#loader').show();
}
function HideLoader() {
    $('#loader').hide();
}
function getPageHeight() {
    var windowHeight
    if (self.innerHeight) {	// all except Explorer
        windowHeight = self.innerHeight;
    } else if (document.documentElement && document.documentElement.clientHeight) { // Explorer 6 Strict Mode
        windowHeight = document.documentElement.clientHeight;
    } else if (document.body) { // other Explorers
        windowHeight = document.body.clientHeight;
    }
    return windowHeight;
}

// getPageScroll() by quirksmode.com
function getPageScroll() {
    var xScroll, yScroll;
    if (self.pageYOffset) {
        yScroll = self.pageYOffset;
        xScroll = self.pageXOffset;
    } else if (document.documentElement && document.documentElement.scrollTop) {	 // Explorer 6 Strict
        yScroll = document.documentElement.scrollTop;
        xScroll = document.documentElement.scrollLeft;
    } else if (document.body) {// all other Explorers
        yScroll = document.body.scrollTop;
        xScroll = document.body.scrollLeft;
    }
    return new Array(xScroll, yScroll)
}