boys clothing sizes 5/6, 6/7, 7/8, 8/10 (pants & underwear)

Our school closet has a very low inventory when it comes to little boys clothing sizes 5-10.  We could use gently used or new pants (kids seem to typically prefer elastic waist joggers/sweatpants, athletic pants.) but we are also receptive to jeans as well for when the weather gets cooler.   We can also use new underwear in the same sizes.    These clothes are utilized if a child has an accident, gets sick or has a spill at lunch.