Leaky shower head - shower stall, old Delex. What do I need?

typically delex is made by the famous (delta) brand.........if your shower head leaks , im uming dripping , yes, you can still purchase parts at home depot, lowe's etc....since you have a single lever faucet, you will need to replace the main cartridge, two small rubber washers with the two springs that sit behind it... normally, a kit can be purchased, just take the parts to lowe's and repairing will be cheap.......