var win_open = new Array(n);
for (i=0; i <= n; i++)
win_open[i] = false;

var win1 = new Array(n);
function popup(winnum, mylink, windowname, winheight, winwidth, myscrollbars)
{
if (!win_open[winnum] || win1[winnum].closed) {
	win1[winnum] = window.open(mylink,windowname,'height=' + winheight + ',width=' + winwidth + ',scrollbars=' + myscrollbars + ',status=no,toolbar=no,menubar=no,location=no,resize=no');
	win_open[winnum] = true;
	}
	else
	win1[winnum].focus();

}