//assume data in book1 and result in book2
dataset xx;
int ncrossing;
int nout;
range xout=[book2]1!1;

range myBook=[book1];
nout = 1;
for(int ns=1; ns<=myBook.nLayers;ns++)
{
	range mydata=[book1]$(ns)!(1,2);//assume XY
	levelcrossing iy:=mydata nc:=nn oy:=xx;
	if(nn>0) //has at least one crossing, get the first
	{
		xout[nout]=xx[1];
		nout++;
	}
}