// Class loader, shows loading icon on a screen
function BigLoader()
{
	document.write("<div id='big-loading' style='position:absolute;top:50%;left:45%;width:100px;height:100px;visibility:hidden;'><img src='images/ajax-loader.gif'></div>");
}

//method show 'loading' icon
BigLoader.prototype.show_loader = function()
{
	var loading_div = document.getElementById('big-loading');
	loading_div.style.top=getScreenCenterY() + 'px';
	loading_div.style.visibility = 'visible';
}

//method hide 'loading' icon
BigLoader.prototype.hide_loader = function ()
{
	var loading_div = document.getElementById('big-loading');
	loading_div.style.visibility = 'hidden';
}

//method checks if 'loading' icon is shown
BigLoader.prototype.is_shown_loader = function ()
{
	var loading_div = document.getElementById('big-loading');
	if (loading_div.style.visibility == 'visible')
		return true;
	else
		return false;

}


// end of class BigLoader