B1/2 visa rejected help need

[perlperl]

Hi,

I am on H1 inviting my parents
My parents B1 got rejected twice.
What is the best way to reapply...after how many months...
if they go to singapore and get the singapore stamp on passport, can that be a positive side while reapplying for US visa?

Your suggestion is highly appreciated

[ramkris]

B1/2 visa rejected help need

Any reason for rejecting?