function tellafriend(ca) {
	var x,y;	
	x = screen.availWidth / 2 - 150;
	y = screen.availHeight / 2 - 150;
	var detail = window.open("tellafriend.xhtml?ca="+ca,"tellafriend","width=550,height=350,left="+x+",top="+y+",scrollbars=yes");
	detail.focus();
}