// Pop-up a new window
function popWin(url,wid,hei,scr) {
	// Work out where to place window (centre)
	if (wid < window.screen.width) {
		pos_x = (window.screen.width/2)-(wid/2);
		pos_y = (window.screen.height/2)-(hei/2);
	}
	var theOptions = "toolbar=0,location=0,directories=0,status=no,menubar=0,scrollbars=" + scr + ",resizable=0,width=" + wid + ",height=" + hei + ",top=" + pos_y + ",left=" + pos_x;
	var theWin = window.open(url,randNum(),theOptions);
	theWin.resizeTo(wid,hei);
	//theWin.moveTo(pos_x,pos_y);
	theWin.focus();
}

// Random number generator
function randNum() {
	return Math.floor(Math.random()*1000001);
}