advance invoicing to the vendor before material delivery

Hi Everyone...

My issue is i am having PO of 100 quantity but vendor gave me 50 of it and i did GR of that and another 50 he will give me in another some days but he want Invoice of 100 from me.is it possible for me to make IR of 100 while i have received only 50 i.e half quantity of it.

help me

Thanks to Everyone,

Regards

Omkar