function get_scroll_position() {
 var scroll_x = 0, scroll_y = 0;
 if (typeof( window.pageYOffset ) == 'number') { // Netscape
  scroll_y = window.pageYOffset; scroll_x = window.pageXOffset;
 }
 else if (document.body && (document.body.scrollLeft || document.body.scrollTop)) { // DOM
  scroll_y = document.body.scrollTop; scroll_x = document.body.scrollLeft;
 }
 else if (document.documentElement && (document.documentElement.scrollLeft || document.documentElement.scrollTop)) { // IE6
  scroll_y = document.documentElement.scrollTop; scroll_x = document.documentElement.scrollLeft;
 }
 return scroll_y;
}

function toggle(div_id) {
	var el = document.getElementById(div_id);
	if ( el.style.display == 'none' ) {	el.style.display = 'block';}
	else {el.style.display = 'none';}
}
function blanket_size(popUpDivVar) {
	if (typeof window.innerWidth != 'undefined') {
		viewportheight = window.innerHeight;
	} else {
		viewportheight = document.documentElement.clientHeight;
	}
	if ((viewportheight > document.body.parentNode.scrollHeight) && (viewportheight > document.body.parentNode.clientHeight)) {
		blanket_height = viewportheight;
	} else {
		if (document.body.parentNode.clientHeight > document.body.parentNode.scrollHeight) {
			blanket_height = document.body.parentNode.clientHeight;
		} else {
			blanket_height = document.body.parentNode.scrollHeight;
		}
	}
	var blanket = document.getElementById('blanket');
	blanket.style.height = blanket_height + 'px';
	var popUpDiv = document.getElementById(popUpDivVar);
	popUpDiv_height=get_scroll_position() + (window.innerHeight/2)-150;//150 is half popup's height
	popUpDiv.style.top = popUpDiv_height + 'px';
}
function window_pos(popUpDivVar) {
	if (typeof window.innerWidth != 'undefined') {
		viewportwidth = window.innerHeight;
	} else {
		viewportwidth = document.documentElement.clientHeight;
	}
	if ((viewportwidth > document.body.parentNode.scrollWidth) && (viewportwidth > document.body.parentNode.clientWidth)) {
		window_width = viewportwidth;
	} else {
		if (document.body.parentNode.clientWidth > document.body.parentNode.scrollWidth) {
			window_width = document.body.parentNode.clientWidth;
		} else {
			window_width = document.body.parentNode.scrollWidth;
		}
	}
	var popUpDiv = document.getElementById(popUpDivVar);
	window_width=window_width/2-150;//150 is half popup's width
	popUpDiv.style.left = window_width + 'px';
	popUpDiv.style.left = window_width + 'px';
}

function setCookie(c_name,value,expiredays)
{
	var exdate=new Date();
	exdate.setDate(exdate.getDate()+expiredays);
	document.cookie=c_name+ "=" +escape(value)+
	((expiredays==null) ? "" : ";expires="+exdate.toUTCString());
}

function popup(windowname, id) {
	setCookie("temp_id", id, 1);
	blanket_size(windowname);
	window_pos(windowname);
	toggle('blanket');
	toggle(windowname);		
}