private void jButton1ActionPerformed(java.awt.event.ActionEvent evt) {//GEN-FIRST:event_jButton1ActionPerformed
        jLayeredPane1.requestFocus();
        if(jList1.getSelectedIndex()>-1) {
            String item = (String) jList1.getSelectedValue();
            if(!item.contains("->")) {
                //remove any associated aliases
                for(int j=0; j<versions.size(); j++) {
                    if(versions.get(j).endsWith(" -> " + item)) {
                        versions.remove(j);
                        j--;
                    }
                }
            }
            versions.remove(jList1.getSelectedIndex());
            jList1.setListData(versions.toArray());
        }
}//GEN-LAST:event_jButton1ActionPerformed