Peel the mangoes and slice, retaining all the juice. Put the mango slices in a pan with just enough water to cover and bring to boil. when simmering add sugar and extra water if necessary to prevent sticking. Puree the garlic, ginger, rasins and sultanas, then add the spices. When the mango reaches a jam like consistency, add the puree and the salt. stir and allow to simmer, adding water if needed. When it thickens sufficiently, remove from heat. Cool and bottle. Leave for a minimum of 4 weeks before serving.