function popUp(url,winname,width,height,options)
{
	if (options != '') options += ',';
	options += 'width=' + width + ',height=' + height;

	if (screen) {
		var bottom = screen.availHeight;
		var right = screen.availWidth;
		var pos_x = parseInt((right- width)/2) ;
		var pos_y = parseInt((bottom - height)/2);
		options += (',left=' + pos_x + ',top=' + pos_y );
	}
	window.open(url,winname,options);
}