while((i1<v1.size()) && (i2<v2.size())){
k = strcmp((const char*) tree->get_text(v1[i1].first),
(const char*) tree->get_text(v2[i2].first));
comp++;
if (k==0)
{
while((i1<v1.size()) && (i2<v2.size())){
k = strcmp((const char*) tree->get_text(v1[i1].first),
(const char*) tree->get_text(v2[i2].first));
comp++;
if (k==0)
{