function markernamesFromColumnnames() {

	markers = newArray(ojNColumns());
	index=0;
	for (i=1;i<=ojNColumns();i++){
		if(endsWith(ojGetColumnTitle(i),"xpos")){
			markers[index]=substring(ojGetColumnTitle(i), 0, indexOf(ojGetColumnTitle(i), "_"));//find the name before the _
			index++;
		}
	}
	markers=Array.trim(markers,index);
	return markers;

}