Chevrolet Repair: how do i fix a sagging door on my 88 pickup, saggin, chev

Question
how do i fix a sagging door on my 1988 chev 1/2 ton pickup?

Answer
duct tape

but seriously, check why its sagging, bad hinges?
if they need replaced , that may be your issue. if its saggin once closed try realigning the door pin or latch. so it catches higher.  since there aint alot of info in the question, i cannot be  more detailed..