// JavaScript Document
function myPopupRelocate() {
	var scrolledX, scrolledY;
	if( self.pageYOffset ) {
		scrolledX = self.pageXOffset;
		scrolledY = self.pageYOffset;
	} else if( document.documentElement && document.documentElement.scrollTop ) {
		scrolledX = document.documentElement.scrollLeft;
		scrolledY = document.documentElement.scrollTop;
	} else if( document.body ) {
		scrolledX = document.body.scrollLeft;
		scrolledY = document.body.scrollTop;
	}

	var centerX, centerY;
	if( self.innerHeight ) {
		centerX = self.innerWidth;
		centerY = self.innerHeight;
	} else if( document.documentElement && document.documentElement.clientHeight ) {
		centerX = document.documentElement.clientWidth;
		centerY = document.documentElement.clientHeight;
	} else if( document.body ) {
		centerX = document.body.clientWidth;
		centerY = document.body.clientHeight;
	}

	var leftOffset = scrolledX + (centerX - 25) / 2;
	var topOffset = scrolledY + (centerY - 400) / 2;

	document.getElementById("mypopup").style.top = topOffset + "px";
	document.getElementById("mypopup").style.left = leftOffset + "px";
}

function fireMyPopup() {
	myPopupRelocate();
	document.getElementById("mypopup").style.display = "block";
	document.body.onscroll = myPopupRelocate;
	window.onscroll = myPopupRelocate;
}