how do I mend the inside seams unravelled at the arm?

i take it it is a lined jacket/coat.slit lining on seam and sew arm back to main body,may need to bind end with tape before doing repair.when stitched together,slit seam in arm lining and pull body lining through it and sew to make good repair.then sew lining in arm holding together,cannot hide that but will not be seen unless turned inside out,sew close to edge and can overlock if you have that facility

maureen
February 2008